ZIP file decompression inflating vs extracting

Question

I used the cPanel control panel to extract image archive.

While decompressing it displayed a list of all files with information like inflating filename... or extracting filename...

I noticed that for JPEG files it shows as inflating and for GIF files it showed as extracting.

What is the difference in inflating and extracting?

Any type of answer would be helpful.

Answer 1

The ZIP format is foremost a container format which just stores files. 'Extracting' means to get the files out of the container. In addtion, to just store the files, each file can be 'handled' by a compression algorithm (or crypto .. or both .. it's more like a 'filter'). The default 'handler' for files is a compression algorithm called 'deflate'. The reverse of 'deflate' is 'inflate'.

A clever ZIP program can choose which compression (or encryption or both) to use upon each file, based upon the file type; not every filetype works good for compression. Example given: pictures are stored compressed most of the time, so it would be pointless trying to compress it down further. Text files on the other hand can be compressed greatly.

To sum it up:

• 'inflating' decompresses a file and 'extracts' it from the container
• 'extracting' just gets the file out of the container