What do you mean by network topology? Explain the different types of network topologies.

Network topology 

 Network topology refers to the physical or logical layout of devices and connections in a computer network. It defines how devices are interconnected and how data flows between them. Network topology plays a crucial role in determining the efficiency, reliability, and scalability of a network.

There are several types of network topologies, each with its own characteristics and advantages. The main types of network topologies include:

1. Bus Topology:

   - In a bus topology, all devices are connected to a single central cable called a bus or backbone.

   - Data is transmitted along the bus, and each device receives the data packet but only processes it if the packet is addressed to that device.

   - Advantages: Simple to set up and requires less cabling. Well-suited for small networks with few devices.

   - Disadvantages: Susceptible to cable failures, limited scalability, and performance degradation as more devices are added.

2. Star Topology:

   - In a star topology, each device is connected directly to a central hub or switch.

   - All data communication between devices passes through the central hub, which manages data traffic.

   - Advantages: Easy to install, fault isolation (failure of one cable does not affect other devices), and scalability (additional devices can be easily added).

   - Disadvantages: Dependency on the central hub (if it fails, the entire network may be affected), and requires more cabling compared to bus topology.

3. Ring Topology:

   - In a ring topology, devices are connected in a closed loop or ring configuration, with each device connected to exactly two other devices.

   - Data is transmitted sequentially around the ring from one device to the next until it reaches its destination.

   - Advantages: Simple to implement, equal access to the network, and no need for a central hub.

   - Disadvantages: Susceptible to cable failures, difficult to troubleshoot, and limited scalability.

4. Mesh Topology:

   - In a mesh topology, each device is connected to every other device in the network, forming a fully interconnected mesh of connections.

   - Mesh topologies can be either full mesh (every device is connected to every other device) or partial mesh (only selected devices are interconnected).

   - Advantages: High redundancy and fault tolerance (multiple paths for data transmission), and high scalability.

   - Disadvantages: Complex to set up and manage, requires a large number of cables and ports, and high cost.

5. Hybrid Topology:

   - A hybrid topology is a combination of two or more basic network topologies (such as star-bus or star-ring).

   - Hybrid topologies offer flexibility and can be customized to meet specific network requirements.

   - Advantages: Combines the strengths of different topologies, provides redundancy and fault tolerance, and supports various network configurations.

   - Disadvantages: Complexity increases with the combination of multiple topologies, and may require additional hardware and configuration. 

These different types of network topologies offer various trade-offs in terms of simplicity, reliability, scalability, and cost, and the choice of topology depends on the specific requirements and constraints of the network environment.