compressing files

compressing files

1. working with online documents mean that local files frequently need to be uploaded for sharing, or downloaded fto be used for local processing

2. files may me extremely large, which can cause problems with transmission(deliivery) in terms of speed and network usage

3. to reduce this problem, files have to be compressed.(i.e reduced in size) befroe transmission and then expanded after

4. a common method if doing this is to convert the to zip files(zip format)

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

6. there are many different algorithms for doing compression - with most compression software supporting several of these

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

8. quite often the zip file will also contaion some program code (a sequence of instructions) to allow the files within the zip file to be unzipped (know as self-extracting files)

9. there is a wide range of software avaliable for zipping files, with one of the most popular being WinZip