Segments are used to isolate network traffic, and often have specific limitations on their physical size and number of hosts and other physical connections. Sendmail A popular Mail Transport Agent, sendmail is a popular mail processing package used primarily on older Unix systems. A serial communications circuit sends the individual bits over the connection one by one, as opposed to a parallel communication circuit. Most home computer data communications are done over serial links. A server provides information or other services to it's clients .
Most network protocols are client-server based.
While a server usually refers to an entire machine, it's can also be used to refer to a particular daemon on that machine. SGML Acronym for Standard Generalized Markup Language, a generic grammar used as the basis for many document formats. Additional information on SGML is available from w3.org . An acronym for Simple Mail Transport Protocol, which defines a common mechanism for exchanging mail across a network. This protocol is described in RFC number 821 .