# LAN & WAN ## What is a Local Area Network (LAN)? - LANs are networks contained within a **small geographical location** - Examples include an office building, a school campus, or a single home - Typically, **all the hardware used to make a LAN is owned by a single entity** - This makes them more secure than WANs, which have connections owned by third-party companies

A LAN is a network built using hubs and/or switches that connect several devices within a limited area

- It is common for one hub or switch to be connected to a router, which will allow the LAN to connect to other networks, such as the Internet ### Advantages of a LAN - **Centralised management** - A LAN allows centralised management of updates, backups and software installations - System administrators can push updates to all machines from a single location - **Security** - A LAN can secure its devices with the use of firewalls, antivirus software and other security features to prevent unauthorised access - Network-level protection can be implemented uniformly - **File Sharing and collaboration** - A LAN allows users on the network to share resources such as printers and other peripherals - Users of the network can also collaborate and share files and folders - Multiple users can access the same document simultaneously ### Disadvantages of a LAN - If hardware fails, the network may not function properly or even at all - A failed switch could disconnect an entire section of the network - Networks are more prone to attacks than standalone computers - A single vulnerability can potentially compromise all connected devices - Access to data and peripherals can be slow depending on network traffic when compared to locally stored data and locally connected peripherals - Peak usage times can create bottlenecks - **Maintenance** - LAN networks require maintenance to ensure that software is up to date - Upgrades and backups can be costly - Dedicated IT personnel may be required ## What is a Wide Area Network (WAN)? - WANs are **collections of LANs spread over a large geographical area** - E.g. a company may connect two LANs between two cities to create a WAN - A multinational corporation might connect offices across different countries

A WAN connects multiple LANs across large distances, typically using third-party infrastructure

- The individual LANs are usually connected via **third-party connections** - e.g. leased lines from ISPs or Telecommunications companies - The organisation doesn't own all the infrastructure between sites

The Internet itself is the largest example of a WAN, connecting networks globally

## Key Differences Between LANs and WANs | Feature | LAN | WAN | |---------|-----|-----| | **Geographical coverage** | Small area (single building, campus) | Large area (cities, countries) | | **Ownership** | Typically owned by single organisation | Uses third-party infrastructure | | **Speed** | Higher data transfer rates | Lower data transfer rates due to distance | | **Security** | More secure (owned infrastructure) | Less secure (shared infrastructure) | | **Cost** | Lower setup and maintenance costs | Higher costs due to leased lines | | **Example** | School computer network | Bank branch network across a country | ## Worked Examples ### Example 1: Defining a WAN **Question:** The Internet can be considered an example of a WAN. Describe what is meant by the term 'WAN'. *2 marks* **How to answer:** - For 2 marks, you need to make 2 points about what a WAN is - Since the question uses WAN as an acronym, it is a good idea to show you know what WAN stands for **Example answer that would get full marks:** A WAN (short for Wide Area Network) is a network spread over a large geographical area such as multiple cities or countries. --- ### Example 2: Characteristics of a LAN **Question:** A chain of restaurants has locations across the country. Each restaurant has its own Local Area Network (LAN). The company wants to connect the restaurants in a Wide Area Network (WAN). Describe two characteristics of a LAN. *2 marks* **How to answer:** - You need to make 2 points about how a LAN is different from a WAN: - LANs cover a small geographical area - The hardware that makes up the LAN is typically owned by one company - For this reason, a LAN is considered to be more secure than a WAN **Example answer that would get full marks:** LANs are considered more secure than WANs since the LAN's connections are owned by the organisation that owns the LAN. LANs cover a small geographical area such as a single building or site.