Can someone give me an understanding of what Sync does

[DennisOS2]

Never use a word to define that word. I came here to find out what the word "sync" means. You tell me in essence that "when you sync something, you sync it." That does not help at all.

this may be too late, but here's my input ....

Agreed. This is an Android forum where one comes for accurate answers to questions involving the OS. That said, the term sync can be used with any OS. It means to make the file content in any two folders identical. This happens when the two target folders are examined by an app used for syncing to see the difference in the files that reside in the two folders. The synching happens when the syncing app copies files from each folder that are not found in the other folder. The result is two identical folders related to each others file content.