Communication engineering
This PDF contains information about Communication.It includes types of system functioms-primary and secondary,hub,switch,brooter,router,gateway,bridge,data link later,error control,flow control,access control,cramming,physical addressing system etc.
computer network
A computer network is a set of computers connected together for the purpose of sharing resources. The most common resource shared today is connection to the Internet. Other shared resources can include a printer or a file server.