Network topologies define the physical or logical layout of interconnected devices within a computer network. Common types include:

1. Bus Topology: In a bus topology, all devices share a single communication line. While simple and cost-effective, the entire network can be affected if the main communication line experiences issues.

2. Ring Topology: Devices in a ring topology are connected in a circular fashion, with data circulating in one direction. This arrangement offers equal access to resources but can be disrupted if one device fails.

3. Star Topology: In a star topology, all devices are connected to a central hub or switch. This design simplifies troubleshooting and allows for easy expansion, but the failure of the central hub can affect the entire network.

4. Mesh Topology: Devices in a mesh topology are interconnected, providing multiple paths for data transmission. This redundancy enhances reliability, but the complexity and cost increase with the number of connections.

5. Hybrid Topology: Hybrid topologies combine two or more different types of topologies. This approach aims to leverage the strengths of different designs while mitigating their weaknesses, offering a balance of efficiency and flexibility.

Each topology has its advantages and considerations, and the choice depends on factors such as the network's size, requirements, and potential for expansion.