BUS topology

In local area networks where bus topology is used, each node is connected to a single cable. Each computer or server is connected to the single bus cable. A signal from the source travels in both directions to all machines connected on the bus cable until it finds the intended recipient. If the machine address does not match the intended address for the data, the machine ignores the data. Alternatively, if the data matches the machine address, the data is accepted. Since the bus topology consists of only one wire, it is rather inexpensive to implement when compared to other topologies. However, the low cost of implementing the technology is offset by the high cost of managing the network. Additionally, since only one cable is utilized, it can be the single point of failure. If the network cable is terminated on both ends and when without termination data transfer stop and when cable breaks, the entire network will be down.

Linear bus
The type of network topology in which all of the nodes of the network are connected to a common transmission medium which has exactly two endpoints (this is the 'bus', which is also commonly referred to as the backbone, or trunk) – all data that is transmitted between nodes in the network is transmitted over this common transmission medium and is able to be received by all nodes in the network simultaneously.
Note: When the electrical signal reaches the end of the bus, the signal "echoes" back down the line, causing unwanted interference. As a solution, the two endpoints of the bus are normally terminated with a device called a terminator that prevents this echo.

Distributed bus
The type of network topology in which all of the nodes of the network are connected to a common transmission medium which has more than two endpoints that are created by adding branches to the main section of the transmission medium – the physical distributed bus topology functions in exactly the same fashion as the physical linear bus topology (i.e., all nodes share a common transmission medium).

Advantages 

1. It is easy to set-up and extend bus network.
2. Cable length required for this topology is the least compared to other networks.
3. Bus topology costs very less.
4. Linear Bus network is mostly used in small networks. Good for LAN.

Disadvantages 

1. There is a limit on central cable length and number of nodes that can be connected.
2. Dependency on central cable in this topology has its disadvantages.If the main cable (i.e. bus ) encounters   some problem, whole network breaks down. 
3. Proper termination is required to dump signals. Use of terminators is must.
4. It is difficult to detect and troubleshoot fault at individual station.
5. Maintenance costs can get higher with time.
6. Efficiency of Bus network reduces, as the number of devices connected to it increases.
7. It is not suitable for networks with heavy traffic. 
8. Security is very low because all the computers receive the sent signal from the source.