Just to explain SHA256 file checksum.
When you download a file from a website, especially an operating system .iso file that you wish to install, it is wise to confirm what you downloaded and stored actually matches the original file. Otherwise you will not know if your file has been corrupted or not.
To do this the provider (Zorin) publishes SHA256 checksums for each of their ZorinOS .iso files.
All you have to do is drag the downloaded file into a app (e.g. quickhash) and copy and paste the checksum text to the same app. The app will compare them and state if they match or not.
See this post: Methods of downloading Zorin OS - #8 by zabadabadoo