IAS Gyan



3rd July, 2022 Prelims


Netwоrk  &  Internet

The  linking  оf  twо  оr  mоre  соmрuting  deviсes  tоgether  fоr  соmmuniсаtiоn  рurроses  оver  а  shаred  interfасe  suсh  аs  the  Internet.  Thаt  meаns  yоu  саn  use  оne  deviсe  tо  send  files  tо  аnоther  deviсe  thrоugh  аnоther  netwоrked  deviсe  suсh  аs  а  rоuter  оr  wireless  ассess  роint.  Yоu  аlsо  might  see  this  term  оften  when  buying  netwоrking  hаrdwаre  like  rоuters  аnd  Wi-Fi  ассess  роints,  thоugh  they  аre  essentiаlly  the  sаme  thing.  Hаrdwаre  mаnufасturers  just  like  tо  mаrket  them  differently  fоr  sоme  reаsоn.

Соmрuter  netwоrks  аllоw  users  tо  shаre  resоurсes  suсh  аs  files,  рrinters  аnd  Internet  ассess.  It  аlsо  аllоws  multiрle  users  tо  рlаy  gаmes  оr  shаre  рiсtures  frоm  оne  сentrаl  deviсe  suсh  аs  а  desktор  соmрuter.  The  mаin  соmроnent  оf  а  netwоrk  is  the  switсh  whiсh  trаnsmits  dаtа  between  different  deviсes.  Аnоther  imроrtаnt  рieсe  оf  hаrdwаre  thаt  suрроrts  netwоrking  is  а  wireless  ассess  роint  (WАР).  WАРs  аllоw  yоur  mоbile  deviсes  tо  соnneсt  tо  the  netwоrk  viа  rаdiо  wаves,  insteаd  оf  using  саbles  like  оther  tyрes  оf  соnneсtiоns  wоuld  require.



Yоu’ve  рrоbаbly  heаrd  оf  this  оne  befоre  аnd  it’s  а  рretty  соmmоn  wireless  teсhnоlоgy  used  tоdаy  tо  соnneсt  deviсes  like  mоbile  рhоnes,  tаblets  аnd  lарtорs  tо  the  Internet.  The  twо  stаndаrds  whiсh  bring  WiFi  tо  yоur  mоbile  deviсe  аre  саlled  802.11а  аnd  802.11g  .


Сellulаr  Dаtа    

This  is  аnоther  wаy  thаt  mоbile  deviсes  саn  ассess  the  internet  wirelessly  using  rаdiо  wаves  (RF  fоr  shоrt),  but  сellulаr  dаtа  is  muсh  fаster  thаn  WiFi  beсаuse  it  uses  high-sрeed  fibre  орtiс  netwоrks  whiсh  ISРs  usuаlly  оwn  аnd  орerаte  themselves.  Sо  whenever  yоu  use  LTE  оr  4G,  yоu’re  асtuаlly  соnneсting  tо  the  Internet  оver  а  сellulаr  соnneсtiоn  insteаd  оf  WiFi.



Аlsо  knоwn  аs  Virtuаl  Рrivаte  Netwоrks,  they  аllоw  users  tо  сreаte  seсure  соnneсtiоns  between  different  sites  оver  the  internet.  This  lets  yоu  ассess  а  соmраny’s  internаl  netwоrk  frоm  а  remоte  lосаtiоn  аnd  even  shаre  files  thrоugh  it.  Аs  аn  exаmрle,  if  yоur  hоme  соmрuter  is  соnneсted  tо  а  VРN,  оther  deviсes  оn  thаt  sаme  netwоrk  саn  see  eасh  оther  while  аlsо  being  аble  tо  соnneсt  tо  files  оn  yоur  соmрuter  withоut  needing  its  IР  аddress  оr  DNS  settings.

Internet  –  The  mоst  fаmоus  netwоrk  in  the  wоrld  thаt  соntаins  аll  оf  the  sites  аnd  serviсes  рeорle  use  оn  а  dаily  bаsis.  Yоu  саn  think  оf  it  аs  оne  mаssive  hаrd  drive  thаt  аnyоne  with  аn  internet  соnneсtiоn  саn  ассess,  suсh  аs  when  yоu  орen  uр  yоur  brоwser  аnd  tyрe  in  а  website’s  аddress.


This  is  just  аnоther  term  fоr  а  lаrge-sсаle  internetwоrk  whiсh  аllоws  different  tyрes  оf  соmрuter  netwоrks  tо  соnneсt  with  eасh  оther  оver  lоng  distаnсes.  Fоr  exаmрle,  mоst  ISРs  орerаte  their  оwn  WАNs  sо  they  саn  link  tоgether  mаny  smаller  netwоrks  аnd  рrоvide  them  ассess  tо  the  Internet.


Dоwnlоаd  &  Uрlоаd

Аs  yоu  рrоbаbly  аlreаdy  knоw,  whаt  hаррens  when  yоu  ассess  а  web  раge  оnline  оr  dоwnlоаd  а  file  frоm  sоmewhere?  Well,  when  yоu  dо  this,  the  file  is  usuаlly  first  dоwnlоаded  frоm  yоur  соmрuter’s  сurrent  lосаtiоn  аnd  then  uрlоаded  tо  аnоther  deviсe  sоmewhere  оn  the  Internet.  Dоwnlоаding  а  file  is  саlled  uрlоаding  it  аs  well,  just  in  reverse!


Сlоud  Соmрuting

This  meаns  thаt  dаtа  саn  be  stоred  оff-site  by  соmраnies  insteаd  оf  being  keрt  lосаl  tо  their  оwn  deviсes.  Fоr  exаmрle,  this  lets  them  ассess  files  оr  run  рrоgrаms  frоm  аny  netwоrked  соmрuter  аll  оver  the  wоrld,  but  сlоud  соmрuting  аlsо  оffers  mаny  оther  benefits  whiсh  yоu  саn  reаd  аbоut  here.



Other Technology Terms


Asymmetric digital subscriber line (ADSL) is a type of digital subscriber line (DSL) broadband technology that is used to connect to the Internet. It uses standard telephone lines to deliver high-speed data communications (up to 24 megabytes per second).



Analogue is a conventional method of transmitting data. Standard landline telephones use analogue technology. It is distinct from digital technology, which provides for greater quality and speed of data transmission.


Assistive technology

Assistive technology refers to any software or hardware that acts to assist and improve the functional capabilities of people with disabilities. Examples include wheelchairs, prosthetics, voice-to-text technology and text-to-speech technology.



Bandwidth refers to the maximum amount of data that can travel a communications path in a given time, usually measured in seconds.



A bit (short for binary digit) is the smallest unit of measurement in computing. 8 bits make up 1 byte.


Boolean operators

Most search engines (e.g. Google) allow you to limit your search or make it more specific by using words such as "and", "or" and "not". These words are known as boolean operators because of their origin as terms in logic.



Computer-aided design (CAD) is a type of software that allows users to create 2D and 3D design and modelling. CAD is used by architects, engineers, artists and other professionals to create precise technical drawings.



A chip is a microprocessor that performs many functions and calculations that make your computer run. Your computer's chip is also referred to as the CPU (Central Processing Unit) or the processor.


Cloud computing

Cloud computing refers to the storing and accessing of data and programs over the Internet instead of on another type of hard drive. Examples of Cloud services include iCloud, Google Cloud and Dropbox.



Encryption is the process of converting electronic data to an unrecognisable or encrypted form, one that cannot be easily understood by unauthorised parties.



Ethernet is the most common way of connecting computers on a network with a wired connection. It is a type of local area network (LAN) technology, providing a simple interface for connecting multiple devices.



A firewall is a barrier that acts as a security system to protect trusted computer systems and networks from outside connections and untrusted networks, such as the Internet.



File transfer protocol (FTP) is a common method of transferring files via the internet from one host to another host.



An internet service provider (ISP) is a company that provides access to the Internet.



An intranet is basically a private, internal internet specific to an organisation or group.



A local area network (LAN) is a system that connects computers and other devices that share a common communications line and wireless link, generally within a limited geographical area such as a home or office building.



"Malware" is short for malicious software. It refers to a software program that has been developed to do harm to other computers. Types of malware include viruses, worms and spyware.



A measure of computer processor storage and real and virtual memory. A megabyte (Mb) is 2 to the 20th power bytes, or 1,048,576 bytes in decimal notation.



Megahertz is the unit used to measure the speed of a computer's processor (e.g. 2.8Ghz)



A modem is a device that allows computers to transmit information to each other via ordinary telephone lines.



Phishing is a type of email fraud in which the perpetrator sends out emails that appear to come from a legitimate service or reputable company, such as a bank or an email service provider. These emails aim to lure recipients to reveal confidential information that the perpetrator can use for their financial advantage - for example, online banking log-in details and passwords.



A software plug-in is a component that adds to a software program's functionality.



A Post office protocol (POP) is an Internet protocol used by your Internet service provider (ISP) to handle email. A POP account is an email account.



SAAS stands for software as a service. It is a software distribution model whereby software applications are centrally hosted and licensed on a subscription basis.



SSL, or secure sockets layer, is a protocol that allows Internet users to send encrypted messages across the Internet. It is generally used when transmitting confidential information (e.g. personal data or credit card details). A web address that begins with "https" indicates that an SSL connection is in use.



Wired equivalent privacy (WEP) is a security protocol used in wi-fi networks. It is designed to provide a wireless local area network (LAN) with a level of security similar to that of a regular wired LAN. WEP-secured networks are usually protected by passwords.



Wi-Fi protected access (WPA) is a security protocol used in wi-fi networks. It is an improvement on WEP because it offers greater protection through more sophisticated data encryption.



Data is stored on a computer in Bytes. A byte is one character, which may be a number or letter. A byte is composed of 8 consecutive bits.

  • 1,000 bytes = 1 kilobyte (K or KB)
  • 1,000 KB = 1 megabyte (MB)
  • 1,000 MB = 1 gigabyte (GB)
  • 1,000 GB = 1 Terabyte (TB)


Virus, Spyware, Trojan, Worm, Malware

These terms are often confused, although they have distinct meanings.

A virus is a piece of software that can copy itself and which attaches itself to some other program in order to survive and replicate. It may have some malicious intent or it may exist simply to reproduce. A worm is similar but it can exist independently; it doesn’t need to attach to a separate program. A Trojan – or Trojan Horse – is a piece of software that gains access to a computer by pretending to be benign or by hiding within some innocent-looking application. The name is obviously derived from the wooden horse employed by the Greek army during the Trojan Wars. Spyware is software that secretly monitors computer activity, attempting to gain private information without the computer user knowing.


By and large, all of the above will have some malicious intent – to harm data, spy on computer activity and so forth. Malware is a general term for all such programs – it simply means any software, of whatever sort, written with a malicious intent. Viruses are generally malware but there is more to malware than just viruses.



CAPTCHA checks are the strings of letters and numbers that have to be typed in on some web pages before something can be saved. They exist because, although humans find interpreting these strings relatively easy, computers do not. Setting up these checks therefore blocks an automated process – such as one generating spam – from using the page, whereas a human is still able to.


The acronym CAPTCHA actually stands for “Completely Automated Public Turing test to tell Computers and Humans Apart” – a rather contrived way of arriving at an acronym that sounds like the word “capture”.



A small text file sent to your computer by a web site you have visited. These can be very useful in that they can allow the web site to recognize who you are when you return. Cookies cannot store viruses or other threats, although they can be used to track your activity across different web sites in order to provide, for example, “targeted” advertisements.


API (Application Programming Interface)

An API is a software go-between that brings information from one application to another. It allows applications to communicate with one another while preserving some security measures for each end point. For example, an API can be used to securely transfer data stored by your web browser to a mobile app.


Big data

Big data is a quick way to refer to the massive amounts of data collected by organizations on a day-to-day basis. Data at this scale can be tapped into for a variety of purposes like trend analyses, forecasting, process automation and more.


DDoS Attacks

A distributed denial-of-service (DDoS) attack is a malicious attempt to disrupt normal traffic to a web property. In computing, a denial-of-service attack is a cyber-attack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to the Internet.



Dynamic Host Configuration Protocol; a protocol that lets a server on a local network assign temporary IP addresses to a computer or other network devices.



The domain name system is how computers convert human-readable domain names and hostnames to numerical IP addresses. When you type howtogeek.com into your web browser’s address bar, your computer contacts its DNS server and the DNS server replies with the numerical IP address of How-To Geek’s server, which is what your computer connects to.



Part of an Internet address. The network hierarchy consists of domains and subdomains. At the top are a number of major categories (e.g., com, edu, gov); next are domains within these categories (e.g., ohio-state); and then there are subdomains. The computer name is at the lowest level of the hierarchy.


Domain Name

Domain names are the base part of website names like howtogeek.com or google.com. Note that domain names are just another type of hostname.


Edge Computing

Edge computing is a distributed computing paradigm that brings computation and data storage closer to the location where it is needed, to improve response times and save bandwidth.


Endpoint Security

Endpoint security is the practice of securing endpoints or entry points of end-user devices such as desktops, laptops, and mobile devices from being exploited by malicious actors and campaigns. Endpoint security systems protect these endpoints on a network or in the cloud from cybersecurity threats.


Exploit Kits

An exploit kit or exploit pack is a type of toolkit cybercriminals use to attack vulnerabilities in systems so they can distribute malware or perform other malicious activities. Exploit kits are packaged with exploits that can target commonly installed software such as Adobe Flash®, Java®, Microsoft Silverlight®.


Gigabyte (Gig or GB)

 1024 x 1024 x 1024 (2 to the 30th power) bytes; it’s usually sufficient to think of a gigabyte as approximately one billion bytes or 1000 megabytes.



HyperText Markup Language; a language used for creating web pages. Various instructions and sets of tags are used to define how the document will look.



The hypertext transfer protocol is the standard protocol modern web browsers and the web itself uses. FTP and BitTorrent are examples of alternative protocols.


Human Firewall

A group of people in an organization that works towards detecting cyber attacks such as ransomware or phishing attacks that may bypass your computer security system.



Infrastructure as a Service; In the most basic cloud-service model, providers of IaaS offer computers – physical or (more often) virtual machines – and other resources.


Information Security Policy:

An information security policy is a set of rules that guide individuals who work with IT assets. Your company can create an information security policy to ensure your employees and other users follow security protocols and procedures.


Internet of Everything (IoE)

 Coined by Cisco, the term “Internet of Everything” is defined as the networked connection of people, process, data, and things. The benefit of IoE is derived from the compound impact of connecting people, process, data, and things, and the value this increased connectedness creates as “everything” comes online.


IoE creates opportunities for organizations, individuals, communities, and countries to realize dramatically greater value from networked connections among people, process, data, and things.


Internet of Things (IoT)

 The Internet of Things, or IoT, refers to the billions of physical devices around the world that are now connected to the internet, all collecting and sharing data.


IP Address

An Internet Protocol address, or IP address, is a numerical address that corresponds to your computer on a network. When a computer wants to connect to another computer, it connects to that computer’s IP address.



Your Internet service provider is the company that provides you with your Internet connection. For example, your ISP may be Comcast, Time Warner, or whatever other company you’re paying each month.



A local area network is a small network that’s confined to a local area. For example, your home network or an office network is a LAN. It connects a group of computers for the purpose of sharing resources such as programs, documents, or printers. Shared files often are stored on a central file server.


Machine Learning

Machine learning is the study of computer algorithms that improve automatically through experience. It is seen as a subset of artificial intelligence.


Managed Antivirus

Managed Antivirus is a centrally managed software option that protects all of the computers at a business from virus threats. The “managed” part means that an IT provider installs the software on a company’s computers and other devices and schedules regular scans to check for issues, as well as ensuring the programs are updated and monitors the health of the network.



Multipurpose Internet Mail Extensions; a protocol that enables you to include various types of files (text, audio, video, images, etc.) as an attachment to an e-mail message.


Multi-Factor Authentication (MFA)

An authentication method in which a computer user is granted access only after successfully presenting two or more pieces of evidence to an authentication mechanism: knowledge, possession, and inherence. Two-factor authentication is a type, or subset, of multi-factor authentication.



A computer that runs a program for converting Internet domain names into the corresponding IP addresses and vice versa.



Network Address Translation; a standard that enables a LAN to use a set of IP addresses for internal traffic and a single IP address for communications with the Internet.



A group of interconnected computers capable of exchanging information. A network can be as few as several personal computers on a LAN or as large as the Internet, a worldwide network of computers.


NIST Framework

The NIST Framework integrates industry standards and best practices to help organizations manage their cybersecurity risks. It provides a common language that allows staff at all levels within an organization—and at all points in a supply chain—to develop a shared understanding of their cybersecurity risks.



Network News Transport Protocol; the protocol used for posting, distributing, and retrieving network news messages.


Platform as a Service (PaaS)

Platform as a service (PaaS) is a complete development and deployment environment in the cloud, with resources that enable you to deliver everything from simple cloud-based apps to sophisticated, cloud-enabled enterprise applications.



Ransomware is a type of malicious software, or malware, designed to deny access to a computer system or data until a ransom is paid. Ransomware typically spreads through phishing emails or by unknowingly visiting an infected website.



A storage area network (SAN) is a dedicated storage network that provides access to consolidated, block level storage. SANs primarily are used to make storage devices (such as disk arrays, tape libraries, and optical jukeboxes) accessible to servers so that the devices appear as locally attached to the operating system. A SAN typically has its own network of storage devices that are generally not accessible through the regular network by regular devices.



 SD-WAN is an acronym for software-defined networking in a wide area network. SD-WAN simplifies the management and operation of a WAN by decoupling the networking hardware from its control mechanism.



The fraudulent practice of sending text messages purporting to be from reputable companies in order to induce individuals to reveal personal information, such as passwords or credit card numbers.



Email spam, also known as junk email or unsolicited bulk email (UBE), is a subset of spam that involves nearly identical messages sent to numerous recipients by email. Definitions of spam usually include the aspects that email is unsolicited and sent in bulk. Spammers collect email addresses from chatrooms, websites, customer lists, newsgroups, and viruses which harvest users’ address books, and are sold to other spammers.


Spear Phishing

Phishing attempts directed at specific individuals or companies is known as spear phishing. In contrast to bulk phishing, spear phishing attackers often gather and use personal information about their target to increase their probability of success.



Small data files that digitally bind a cryptographic key to an organization’s details. When installed on a web server, it activates the padlock and the https protocol (over port 443) and allows secure connections from a web server to a browser. Typically, SSL is used to secure credit card transactions, data transfer and logins, and more recently is becoming the norm when securing browsing of social media sites. SSL Certificates bind together:


A domain name, server name or hostname.


An organizational identity (i.e. company name) and location.


An organization needs to install the SSL Certificate onto its web server to initiate secure sessions with browsers. Depending on the type of SSL Certificate applied for, the organization will need to go through differing levels of vetting. Once installed, it is possible to connect to the website over https://www.domain.com, as this tells the server to establish a secure connection with the browser. Once a secure connection is established, all web traffic between the web server and the web browser will be secure. To view the details of an SSL Certificate, go to a secure site, click on the padlock and select “View Certificate”. All browsers are slightly different, but the Certificate always contains the same information.



Transmission Control Protocol/Internet Protocol; an agreed upon set of rules that tells computers how to exchange information over the Internet. Other Internet protocols like FTP, Gopher, and HTTP sit on top of TCP/IP.


Two-factor authentication (2FA)

An extra level of security achieved using a security token device; users have a personal identification number (PIN) that identifies them as the owner of a particular token. The token displays a number which is entered following the PIN number to uniquely identify the owner to a particular network service. The identification number for each user is changed frequently, usually every few minutes.



Voice phishing, or vishing, is the use of telephony to conduct phishing attacks. Landline telephone services have traditionally been trustworthy; terminated in physical locations known to the telephone company, and associated with a bill-payer.



Voice over Internet Protocol; a means of using the Internet as the transmission medium for phone calls. An advantage is you do not incur any additional surcharges beyond the cost of your Internet access.



Wired Equivalent Privacy; a security protocol for wireless local area networks defined in the 802.11b standard. WEP provides the same level of security as that of a wired LAN.