Server

main computer in a network that provides services to other computers
provides services like
- file storage
- email
- web pages
- database
- etc
Types
- File Server
  - stores and manages files
  - Ex: Google Drive
- Print Server
  - manages one or more printers
  - Ex: Google Cloud Print
- Database Server
  - stores and manages database
  - Ex: MySQL
- Web Server
  - stores and manages web pages
  - Ex: Apache
- Mail Server
  - stores and manages emails
  - Ex: Gmail
- FTP Server
  - stores and manages files for downloading and uploading
  - Ex: FileZilla
- Proxy Server
  - acts as an intermediary b/w client and server
  - Ex: Squid
- DHCP Server
  - assigns IP addresses to computers
  - Ex: DHCP Server
- DNS Server
  - translates domain names to IP addresses
  - Ex: Google DNS
- Telnet Server
  - allows remote login to a computer
  - Ex: Telnet
- Application Server
  - provides business logic to application programs
  - Ex: Apache Tomcat
- Virtual Server
  - allows multiple servers to run on a single physical server
  - Ex: VirtualBox
- Backup Server
  - stores and manages backup files
  - Ex: BackupPC
- Fax Server
  - manages fax machines
  - Ex: HylaFAX
- Groupware Server
  - provides collaboration services
  - Ex: Microsoft Exchange Server
- IRC Server
  - manages Internet Relay Chat
  - Ex: IRC Server
- List Server
  - manages mailing lists
  - Ex: Mailman
- News Server
  - manages Usenet news groups
  - Ex: Leafnode
- Open Source Server
  - manages open source software
  - Ex: SourceForge
- Sound Server
  - manages sound devices
  - Ex: PulseAudio
- Time Server
  - manages time synchronization
  - Ex: NTP
- VPN Server
  - manages virtual private networks
  - Ex: OpenVPN
- Web Proxy Server
  - manages web proxy
  - Ex: Squid
- Windows Server
  - manages Windows computers

Internet

Network of networks that connects billions of computers worldwide
History
- 1960s
  - US Department of Defense (DoD) created ARPANET
  - ARPANET was the first network to use packet switching
  - ARPANET was the first network to use TCP/IP
- 1970s
  - ARPANET was split into ARPANET and MILNET
  - ARPANET was used for research and MILNET was used for military
  - ARPANET was the first network to use email
- 1980s
  - ARPANET was split into ARPANET and NSFNET
  - ARPANET was used for research and NSFNET was used for non-military research
  - ARPANET was the first network to use TCP/IP
- 1990s
  - ARPANET was shut down
  - NSFNET was shut down
  - NSFNET was the first network to use 56 Kbps speed
- 2000s
  - ARPANET was shut down
  - NSFNET was shut down
  - NSFNET was the first network to use 1.5 Mbps speed
- 2010s
  - ARPANET was shut down
  - NSFNET was shut down
  - NSFNET was the first network to use 10 Gbps speed

DNS

DNS :Domain Name Service
Domain Name Server
automatic service that converts domain name to its corressponding ip addressso that web browser can understand ehich browser we we want to access
Types
- Root Name Server
  - manages top-level domains
  - Ex: a.root-servers.net
- Top-Level Domain Name Server
  - manages top-level domains
  - Ex: .com
- Authoritative Name Server
  - manages domain names
  - Ex: google.com
- Local Name Server
  - manages local domain names
  - Ex:
- Forwarding Name Server
  - forwards requests to other name servers
  - Ex:

ISP

Internet Service Provider
provides internet access to customers
Types
- Dial-up
  - uses telephone line
  - Ex: BSNL
- DSL
  - uses telephone line
  - Ex: Airtel
- Cable
  - uses cable TV line
  - Ex: Hathway
- Satellite
  - uses satellite
  - Ex: Tata Sky
- Wireless
  - uses wireless
  - Ex: Jio
- Mobile
  - uses mobile network
  - Ex: Airtel
- Fiber
  - uses fiber optic cable
  - Ex: ACT
- Types
  - Tier 1 ISP
    - connects to the internet backbone
    - All over the world
    - Ex: AT&T
  - Tier 2 ISP
    - In a country
    - Ex: Airtel
  - Tier 3 ISP
    - In a City
    - Ex: MTNL

Difference B/W Internet & Intranet

Internet	Intranet
Public Network	Private Network
Accessible to everyone	Accessible to only employees
Uses Internet Protocol	Uses Internet Protocol
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