File splitting is basically dividing a zip file into two or more smaller pieces that include all the files originally contained in the first zip file. If your original zip file is too large to send via email, one solution is to uncompress it, divide the constituent files up into separate folders, and zip them individually to send across multiple emails. But with WinZip, it’s now much quicker and easier to simply split one zip file into multiples that you can then attach to several emails. It saves a huge amount of time and ensures that you don’t accidentally leave out any important files like you might do if you were to split files manually.