The word under is the most common. It is usually used for three-dimensional objects:
Under can be used both when the objects are touching (as in the papers and magazine) and when the objects are not touching (as in the cat and table).
You can also use “under” with numbers to mean “less than”:
The word below is often used when describing levels or limits:
It is also used to describe something on a lower position on a page:
Beneath and underneath are just more formal words for under: