Computer Networks Fundamentals

A computer network is a collection of interconnected devices that communicate with each other to share resources and exchange data.
Network devices include computers, servers, printers, routers, switches, and modems.
Network topologies: Bus, Star, Ring, Mesh, and Hybrid.

LAN (Local Area Network): Connects devices in a limited geographical area, such as a home, office building, or campus.
WAN (Wide Area Network): Connects devices over a larger geographical area, such as a city or country.
MAN (Metropolitan Area Network): Connects devices in a metropolitan area, such as a city or town.
WLAN (Wireless Local Area Network): Connects devices wirelessly in a limited geographical area.
Internet: A global network of interconnected computers and servers that communicate using standardized protocols.

TCP/IP (Transmission Control Protocol/Internet Protocol): The most widely used protocol suite for computer networks.
HTTP (Hypertext Transfer Protocol): A protocol used for transferring data over the internet.
FTP (File Transfer Protocol): A protocol used for transferring files over a network.
DNS (Domain Name System): A protocol used for resolving domain names to IP addresses.

Client-Server Architecture: A network architecture where clients request services from servers.
Peer-to-Peer Architecture: A network architecture where devices act as both clients and servers.

Firewall: A system that controls incoming and outgoing network traffic based on predetermined security rules.
Encryption: The process of converting plaintext data into ciphertext to protect it from unauthorized access.
Authentication: The process of verifying the identity of a user or device on a network.

Bandwidth: The amount of data that can be transmitted over a network in a given time.
Latency: The delay between sending and receiving data over a network.
Throughput: The amount of data that is successfully transmitted over a network in a given time.

A computer network consists of interconnected devices that share resources and exchange data.
Key network devices include computers, servers, printers, routers, switches, and modems.
Common network topologies are Bus, Star, Ring, Mesh, and Hybrid, each defining the layout and connections among devices.

LAN (Local Area Network): Connects devices within a limited geographical area, like homes or offices.
WAN (Wide Area Network): Covers larger geographical areas, such as cities or countries.
MAN (Metropolitan Area Network): Connects devices across a metropolitan area, typically a city.
WLAN (Wireless Local Area Network): Allows wireless connectivity within a limited area.
Internet: A vast global network connecting millions of computers and servers through standardized protocols.

TCP/IP (Transmission Control Protocol/Internet Protocol): The foundational protocol suite for the internet and most networks.
HTTP (Hypertext Transfer Protocol): Protocol critical for data transfer over the internet, especially for web pages.
FTP (File Transfer Protocol): Used for transferring files across computer networks.
DNS (Domain Name System): Resolves domain names to IP addresses, enabling users to access websites easily.

Client-Server Architecture: Involves clients that request services from centralized servers, managing resources effectively.
Peer-to-Peer Architecture: Allows devices to function as both clients and servers, promoting direct resource sharing among users.

Firewall: Acts as a barrier, controlling incoming and outgoing traffic based on specified security policies.
Encryption: Transforms readable data (plaintext) into unreadable formats (ciphertext) to prevent unauthorized access.
Authentication: Confirms the identity of users or devices trying to access the network, ensuring security protocols are followed.

Bandwidth: Measures the volume of data transmitted over a network within a specific timeframe, crucial for data transfer rates.
Latency: Refers to the time delay experienced between sending and receiving data, impacting responsiveness.
Throughput: Indicates the actual rate of successful data transfer across the network within a given time period, affected by various factors like bandwidth and latency.