A
file in a compressed
format. Many
operating systems and
applications contain
commands that enable you to pack a file so that it takes up less
memory. For example, suppose you have a
text file containing ten consecutive space
characters. Normally, this would require ten
bytes of
storage. However, a
program that packs files would replace the space characters by a special
space-series character followed by the number of spaces being replaced. In this case, the ten spaces would require only two bytes. This is just one packing technique -- there are many others. One disadvantage of packed files, however, is that they can be
read only by the program that packed them because they contain special codes.
Some modems automatically pack data before transmitting it across communications lines. This can produce faster communication because fewer bytes need to be sent. However, the modem on the receiving side must be capable of unpacking the data.
Packing is often referred to as data compression, particularly when it involves data communications.
