Network topology refers to the physical or logical layout of a computer network. It describes how devices are connected to each other and how data flows within the network. There are various types of network topologies, including:

1. Bus Topology: All devices are connected to a central cable (bus). Data is transmitted in both directions along the bus.

2. Ring Topology: Devices are connected in a circular loop. Each device receives data from one device and sends it to the next device until it reaches the intended recipient.

3. Star Topology: All devices are connected to a central switch or hub. Data is transmitted through the central device, which facilitates communication between devices.

4. Mesh Topology: Every device is connected to every other device in the network. Data can take multiple paths to reach its destination, improving redundancy and fault tolerance.

5. Tree Topology: Devices are arranged in a hierarchical structure, resembling a tree. Multiple star topologies may be connected together through a central backbone to form a wider network.

6. Hybrid Topology: A combination of two or more different topologies to form a larger, more complex network.

Each topology has its own advantages and disadvantages, and the choice of topology depends on factors such as scalability, reliability, cost, and the specific needs of the network.