It is often useful to compress a file (or files) to make them smaller - especially if you need to send them via email
Windows has a built in feature to do this called Compressed Folders
To create a zip file firstly find the file/files you wish to compress and select them with the mouse
Windows XP, Vista and 7: Next right mouse click on the files and choose Send to > Compressed (zipped) folder
Windows 8 / 10: Click Zip on the Share toolbar in File Explorer (as highlighted above)
Windows will then compress the files for you and create the .zip file