Networks allow computers to communicate and share resources. Understanding network types and protocols is fundamental to modern computing.
Types of Networks
Networks are classified by their geographical scope and the area they cover.
LAN (Local Area Network)
Definition
A LAN (Local Area Network) covers a small geographical area, typically a single building or campus. It is owned, managed, and maintained by a single organisation.
Key Point
| LAN characteristic | Details |
|---|---|
| Coverage | Small area (building/campus) |
| Typical speed | High speed (about 100Mbps to 10Gbps) |
| Ownership | Usually one organisation |
| Latency | Low latency / fast response |
| Typical hardware | Switches, routers, access points |
| Common examples | School, office, home network |
WAN (Wide Area Network)
Definition
A WAN (Wide Area Network) spans large geographical areas - cities, countries, or even continents. The Internet is the largest WAN.
Key Point
| WAN characteristic | Details |
|---|---|
| Coverage | Large area (city/country/global) |
| Infrastructure | Often leased telecom links |
| Ownership | May involve multiple organisations |
| Latency | Higher than LAN |
| Typical speed | Usually lower than LAN over distance |
| Common examples | Internet, multi-office enterprise WAN |
Other Network Types
Key Point
| Network type | Scope | Typical technology/example |
|---|---|---|
| PAN | Around one person | Bluetooth/NFC (phone ↔ earbuds) |
| MAN | City or large campus | City-wide Wi-Fi / municipal network |
Network Protocols
For devices to communicate, they must follow agreed rules - these are called protocols.
Definition
A protocol is a set of rules that governs how data is transmitted and received over a network. Protocols ensure devices from different manufacturers can communicate.
Key Point
| Protocol | Full name | Main purpose |
|---|---|---|
| HTTP | Hypertext Transfer Protocol | Access web pages (unencrypted) |
| HTTPS | HTTP Secure | Access web pages securely (encrypted) |
| TCP | Transmission Control Protocol | Reliable data delivery |
| IP | Internet Protocol | Addressing and routing |
| FTP | File Transfer Protocol | File transfer |
| SMTP | Simple Mail Transfer Protocol | Send email |
| POP3 | Post Office Protocol v3 | Download email (often removes from server) |
| IMAP | Internet Message Access Protocol | Manage email while keeping mail on server |
| DNS | Domain Name System | Domain name to IP translation |
Why Protocols and Standards Matter
Definition
A standard is an agreed specification that manufacturers and developers follow, so that hardware and software made by different companies work together. A protocol is a standard for communication.
Key Point
Importance of protocols and standards:
• The sending device has no direct control over how the receiving device behaves, so both must follow the same rules
• Data is exchanged in a predictable way: both ends agree the format of the data, how it is addressed, how errors are detected and how a connection starts and ends
• Devices and software from different manufacturers are compatible with each other
• Without them, a device could only communicate with others made by the same company
• Examples of standards: Ethernet, Wi-Fi, TCP/IP and HTML
• The sending device has no direct control over how the receiving device behaves, so both must follow the same rules
• Data is exchanged in a predictable way: both ends agree the format of the data, how it is addressed, how errors are detected and how a connection starts and ends
• Devices and software from different manufacturers are compatible with each other
• Without them, a device could only communicate with others made by the same company
• Examples of standards: Ethernet, Wi-Fi, TCP/IP and HTML
Advantages and Drawbacks of Networking
Key Point
Advantages of connecting computers in a network:
• Hardware such as printers can be shared
• Files can be shared and worked on together
• One internet connection can be shared
• Users can log on and reach their files from any machine
• Security, backups and software updates can be managed centrally
• User activity can be monitored and access levels controlled
Drawbacks:
• The hardware, cabling and staff to manage the network all cost money
• Malware can spread between connected machines
• Data can be accessed without authorisation if security is weak
• If a central device such as a server or switch fails, many users are affected
• Hardware such as printers can be shared
• Files can be shared and worked on together
• One internet connection can be shared
• Users can log on and reach their files from any machine
• Security, backups and software updates can be managed centrally
• User activity can be monitored and access levels controlled
Drawbacks:
• The hardware, cabling and staff to manage the network all cost money
• Malware can spread between connected machines
• Data can be accessed without authorisation if security is weak
• If a central device such as a server or switch fails, many users are affected