Virtual Private Network - A Virtual Private Network, or VPN, is a private network of computers that's at least partially connected by public phone lines. A good example would be a private office LAN that allows users to log in remotely over the Internet (an open, public system). VPNs use encryption and secure protocols like PPTP to ensure that data transmissions are not intercepted by unauthorized parties.

Wide Area Network - Take two local area networks, hook them together, and you've got a WAN. Wide area networks can be made up of interconnected smaller networks spread throughout a building, a state, or the entire globe.

What You See Is What You Get - Pronounced "whizzy-wig"

This is a protocol for transferring files during direct dial-up communications. Developed by Ward Christensen in 1977, Xmodem has basic error checking to ensure that information isn't lost or corrupted during transfer; it sends data in 128-byte blocks. Xmodem has undergone a couple of enhancements: Xmodem CRC uses a more reliable error-correction scheme, and Xmodem-1K transfers data faster by sending it in 1,024-byte blocks.

This is a protocol for transferring files during direct dial-up communications. So named because it builds on the earlier Xmodem protocol, Ymodem sends data in 1,024-byte blocks and is consequently faster than Xmodem. However, it doesn't work well on noisy phone lines, unlike its successor, Zmodem. Ymodem has undergone a few enhancements: Ymodem-Batch can send several files in one session; Ymodem-G drops software error correction, which speeds up the process by leaving hardware-based error correction in modems.

In a graphics card, this section of video memory keeps track of which onscreen elements can be viewed and which are hidden behind other objects.

This file transfer protocol should be your first choice for sending and receiving files using dial-up connections. Zmodem's speed and error checking recommend it, and it can resume a file transfer after a break in communications, so make sure this protocol is available in your communications software and any BBS you dial into. In case you couldn't tell, it's so named because it's intended to supersede Xmodem and Ymodem.