Networks

Network Basics

A network is a set of interconnected computers, servers, and other devices that communicate and exchange information.
Local Area Networks (LANs) are small networks located in a specific geographical area like a school or a home.
Wide Area Networks (WANs) are large networks that span cities, countries or even the globe.
Networks can either be wired, where devices are connected using cables, or wireless, where devices are connected via signals such as Wi-Fi.
The Internet is the largest example of a WAN, connecting computers and networks all around the world.

A router is a device that directs data across a network, ensuring it gets from the source to the right destination.
Switches are used to connect multiple devices on a LAN and direct data to the correct device on the network.
Modems are devices that provide internet connectivity by converting signals from your ISP so that they can travel over your home network.

Network operating systems (NOS) are software designed to manage and coordinate networked computers. They provide features such as file sharing, printer sharing, and multi-user applications.
Firewall software is used to prevent unauthorized access to a network, helping to increase its security.
Anti-virus software scans files or your computer’s memory for certain patterns that may indicate an infection.

Network security involves protecting a network from unauthorized access and potential threats.
Measures can include using firewalls, installing anti-virus software, and encrypting sensitive data.
Phishing is a common method of attack where an attacker pretends to be a trustworthy entity in order to steal sensitive data like usernames, passwords, and credit card details.

TCP/IP (Transmission Control Protocol/Internet Protocol) is the basic communication language or protocol of the internet.
HTTP (Hypertext Transfer Protocol) and HTTPS (HTTP Secure) are protocols used for transmitting hypertext over the internet.
FTP (File Transfer Protocol) is used to transfer files from one host to another over the internet.
POP3, IMAP, and SMTP are protocols used for sending and receiving emails.

Benefits: Data sharing is easier; hardware like printers can be shared, reducing costs; users can communicate using email, instant messaging, etc.
Drawbacks: Setup and maintenance can be expensive; security risks from hackers; if a server fails, all connected computers may be affected.