To copy data (usually an entire file) from a main source to a peripheral device. The term is often used to describe the process of copying a file from an online service or bulletin board service (BBS) to one's own computer. Downloading can also refer to copying a file from a network file server to a computer on the network.
In addition, the term is used to describe the process of loading a font into a laser printer. The font is first copied from a disk to the printer's local memory. A font that has been downloaded like this is called a soft font to distinguish it from the hard fonts that are permanently in the printer's memory.
The opposite of download is upload, which means to copy a file from your own computer to another computer.