POP |
P Short for Post Office Protocol, a
protocol used to retrieve e-mail from a mail server. Most e-mail
applications (sometimes called an e-mail client) use the POP protocol,
although some can use the newer IMAP (Internet Message Access Protocol).
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PAL | Short for Phase Alternating Line, the dominant television standard in Europe. The United States uses a different standard, NTSC. Whereas NTSC delivers 525 lines of resolution at 60 half-frames per second, PAL delivers 625 lines at 50 half-frames per second. Many video adapters that enable computer monitors to be used as television screens support both NTSC and PAL signals. |
Push-Pull | Push- In
client/server applications, to send data to a client without the client
requesting it. The World Wide Web is based on a pull technology where the
client browser must request a Web page before it is sent. Broadcast media,
on the other hand, are push technologies because they send information out
regardless of whether anyone is tuned in.
Pull-To request data from another program or computer. The opposite of pull is push, where data is sent without a request being made. The terms push and pull are used frequently to describe data sent over the Internet. The World Wide Web is based on pull technologies, where a page isn't delivered until a browser requests it. Increasingly, however, Information services are harnessing the Internet to broadcast information using push technologies. A prime example is the PointCast Network. |