lan and wifi basics

Local Area Network (LAN):

1. Definition:

  • A LAN is a network that connects computers and devices within a limited geographic area, such as a home, office, or campus.

2. Components:

  • Devices: Computers, printers, servers, and other devices connected to the network.
  • Networking Hardware: Routers, switches, hubs, and network cables.

3. Topology:

  • LANs can have various topologies, such as star, bus, ring, or a combination (hybrid).

4. Protocols:

  • Ethernet: Most common LAN technology, uses CSMA/CD (Carrier Sense Multiple Access with Collision Detection) protocol.
  • TCP/IP: Suite of protocols for data exchange.

5. Addressing:

  • MAC Address: Unique hardware address assigned to each network interface card (NIC).
  • IP Address: Logical address assigned to devices for communication within the network.

6. Transmission Media:

  • LANs use different types of cables (e.g., Ethernet cables) for wired connections.

7. Switching:

  • Modern LANs often use switches for efficient data transfer, reducing collisions compared to older technologies like hubs.

8. Security:

  • Security measures include firewalls, VLANs (Virtual Local Area Networks), and encryption.

9. Data Transfer:

  • LANs provide high data transfer rates (e.g., 1 Gbps or 10 Gbps) within the local network.

Wi-Fi (Wireless Fidelity):

1. Definition:

  • Wi-Fi enables wireless connectivity, allowing devices to communicate without physical cables.

2. Components:

  • Wireless Access Points (WAPs): Devices that enable wireless communication.
  • Wireless Network Interface Cards (WNICs): Installed in devices like laptops, smartphones, and tablets.

3. Frequency Bands:

  • Wi-Fi operates in 2.4 GHz and 5 GHz frequency bands, providing multiple channels for communication.

4. Modulation Techniques:

  • Wi-Fi uses modulation techniques (e.g., QAM - Quadrature Amplitude Modulation) for transmitting data wirelessly.

5. Security:

  • WPA (Wi-Fi Protected Access) and WPA2/WPA3 protocols enhance security, including encryption and authentication.

6. Standards:

  • IEEE 802.11 standards (e.g., 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.11ax) define Wi-Fi specifications.

7. Data Transfer:

  • Wi-Fi data transfer rates vary based on standards (e.g., from Mbps in older standards to Gbps in newer ones).

8. Interference:

  • Interference from other electronic devices or neighboring Wi-Fi networks can affect performance.

9. Range:

  • Wi-Fi has a limited range, affected by factors like obstacles and signal strength.

LANs provide wired local connectivity, while Wi-Fi offers wireless connectivity, both serving the purpose of connecting devices within a defined area. The choice between LAN and Wi-Fi depends on factors like data transfer requirements, mobility, and infrastructure constraints.