In the simplest terms, what is the difference between synchronize to repository and update to HEAD?

Question

I have seen the question answered on this and other sites, but in terms that only left me more confused. I often encounter an issue where I'm trying to commit code but am told that my file(s) is out of date and I never know which of those two things I'm supposed to do first. On top of that, it seems that synchronize with repository will often delete things in my files which I don't want it to do; I only want to import additions (added lines to files or new files altogether) and changes from the repository, I don't want anything deleted from my files. Thanks for any information.

Answer 1

with repository will often delete things in my files which I don't want it to do

Running svn update does not delete files with local modifications. Therefore, it is unclear what kind of issue you are asking about.