A Zip File is a compression archive file, which means a single Zip file may contain one or more files in it. Procedure to open or extract a Zip file depends on the operating system installed on the computer.
If your are using Windows XP or later, then you don’t have to install anything to open a Zip File. You will notice zip file with big yellow icon (with zip like figure running across the icon). To open, double click on the zip file and you will see new explorer like window with contents of Zip file. You can copy those contents to any other folder / location of your choice.
For Windows 95, 98, ME, 2000 you need to install addition utility to able to open zip files. Traditionally, we use Winzip software but other the years it has become bloated with extra features which are of no use for an average computer user. To able to open Zip Files you can download and install either of: WinRAR, 7 Zip and WinZip.