POP - technical definition

Point Of Presence. The point at which an interexchange carrier (IXC) establishes a physical presence in a geographic area, and at which the local exchange carriers (LECs) terminate access services. The term GigaPOP is sometimes used in reference to a POP with bandwidth in the Gbps range. See also access circuit, GigaPOP, LEC, and IXC.
Post Office Protocol. An IETF standard for a store-and-forward service used by a client to retrieve e-mail from a remote server over an IP network. The current version is POP3 (Post Office Protocol version 3). See also client, e-mail, IETF, IP, POP3, and server.