svn - when will I see conflicts?

Question

I am just starting a new position and using svn rather than git (my favorite).

With svn if there are any conflicts will I see them after an svn update or after an (attempt) to svn commit?

In other words will an svn update merge remote changes into my current (uncommited) working copy?

I want to be sure not to mess up before my first svn commit if things are not good as I am new to this system! :)

Obviously I have also made a manual copy of my new code in case I run into any issues :)

fyi, I am on Ubuntu 11.10