A protocol used by mail clients to download messages from a mail server on the Internet. The older version, POP2, a standard since the mid-1980's, requires SMTP to send messages. The newer version, POP3, can be used with or without SMTP. Some e-mail applications can use the newer Internet Message Access Protocol (IMAP). Also, the abbreviation for Point of Presence; being the closest site where a user can connect to an Internet server or other remote server; or, the location where a line from a long-distance telephone carrier makes a local connection. Also, a slang term meaning to remove or retrieve data from a stack of work in progress; the opposite of "push", for adding to the data stack. Also, the abbreviation for Point of Purchase; being a computer terminal or vending machine situated in a store or shopping mall where a customer can view products with their prices and select items to buy. See e-mail.