ZIP archives do a wonderful job of compressing files into a single package. In Windows, you can easily create a ZIP file by selecting some files, right-clicking and going to Send To -> Compressed.
But when you open the ZIP file through Windows, you do not get the option of individually extracting files; Windows automatically extracts the archive. To get more option you need to have a 3rd party compression program installed. If a lack of installation privileges or any other reason does not let you allow such a program, WobZIP is there to solve your problem.