| Client (CPU, hard drive, and monitor)
||The client hosts the browser that allows users to access and display Web resources.
||The server is a computer that is dedicated to storing data or running applications, processes, and services.
||The server stores and forwards URLs and resources (such as Web pages, images, other data).
||The physical connections among network hardware, such as cables, phone lines, or other connection lines. A primary connectivity issue is bandwidth, which is the maximum amount of information that the line can transmit per unit of time. (Home computers often connect via telephone lines, while businesses usually use connections with greater bandwidth, such as T1 lines, ISDN lines, or DSL.)
||Connects two or more IP networks and routes traffic based on IP addresses.
||Interconnects multiple devices in a network, thereby enabling distribution of information among the devices connected to it.
||Used when dial-up services are necessary. When analog telephone lines are used to access the Internet, a modem converts digital to analog signals (outgoing traffic) and from analog to digital (incoming traffic). DSU/CSU modems are used for T1 or fractional lines. Digital modems do not need to convert from digital to analog, but maintain digital from end to end (for example, for use with ISDN or ADSL lines).