compressing files

compressing files

1. working with online documents means that local files frequently need to be uploaded for sharing, or downloaded to be used for loal prosessing

2. files can be large which creates problems when sending in terms of speed and network usage

3. to reduce this problem files have to be compressed in transmission and expanded after

4. common way of doing this is zip files

5. zip files are basically stores of data files which may have been compressed

6. there are many algorisms for doing the compression

7. the last item in a zip file is an index which shows the placement of each of the data files and allows other files to be added

8. quite often the zip file will also contain some program code (a sequence of instructions) to allow the files win the zip file o be unzipped (self-extracting files)

9. there is a wide range of software available for ziping files, with one of he most popular being WinZip