A special disk drive that uses portable disks (about the size of floppy disks) that hold 1 gigabyte of data.
One thousand bits per second (bps). Today's modern modems transmit data at either 28.8Kbps or 56Kbps.
The amount of time it takes for a second character to appear when you press and hold down a key.
1,024 bytes. This is often abbreviated K or KB.