a bus network is a cheap and easy way of using a network. its also very quick sending it across a line and back. the bad things about this are if it breaks off at the server you cant access any files but the good things are that they are easy to replace.
a star network is another network but instead of a line, its a star (hints the name) the star network is a lot better than the bus network, because if one line breaks, the other computers can still work with ease. but this specific type of network is a bit more pricey than the average bus network.