For Mac, Windows and Android systems
How to Create a Password Protected ZIP File – Encrypted and Locked
You want to encrypt a Zip file if you don’t want anyone to be able to open it. A normal, unencrypted Zip file can be viewed in seconds on most operating systems with a simple double-click, revealing all the files inside.
A password-protected, encrypted Zip file prevents this. The archive is locked so that only specific people can access its contents (or anyone lucky enough to have a Zip file unlocker).
There are several reasons to use a Zip archive instead of just storing the files in a folder. What they all have in common is ease of use.