The Internet with its wiring, electronics, addressing and protocols, is used to transmit both requests for pages and the resulting pages between clients and servers. The web is layered on top of the internet. That is, the internet provides an underlying communication system that is used by many systems including the web, telnet, ftp, e-mail and others. The web system is based on the idea of sending files called pages from servers upon request from browser programs on client machines.
Maps have regions of the graphic acting as links to other pages.
Click here for a introductory discussion and example of a map. This is a page. It has this text, the graphic below, and links throughout it. To be a server a machine has to be connected to the net and run a program all the time that responds to requests for these pages from client machines elsewhere. It also needs to run additional programs to handle forms.