For example:-
On my desk, next to my computer I have a lot of paper. When I'm working my dog Laika usually sits under my desk. Next to my desk there is a set of shelves, there are a lot of books on the shelves.
(If you want a bit of fun, you can take a photo of your desk and post it in your profile. Let's see how tidy you are.)
From Learn English Online - Lesson 52 - Prepositions

under my desk.