The layout of the way how the computers in a netword are interconnected is called network tipology.
Some types of network topologies are:
1) Point-to-point tipology: all the computers are connected to each other directly (computer-to-computer, in pairs, this is a direct link between each two computers).
2) Bus topology: all the nodes (computers or server) are connectect to a maing cable.
3) Star topology: all the computers are connected to a central computer or server which is called central hub. This is the layout described in the question.
4) Ring topology: the computers are connectec in a circular path; each computer is connected to the next computer.
5) Mesh: every computer is connected to every other computer.
an educational institutions has a number of buildings in the campus. Each building has its own independent network system, and all these networks connects to the central server located in the administration building. This is called star topology.
Primary memory is directly accessible by Processor/CPU. Secondary memory is not directly accessible by the CPU. ... The memory devices used for primary memory are semiconductor memories. The secondary memory devices are magnetic and optical memories
