Beside and Besides

Take a close look at these words and notice that one has a "s" on the end which changes the meaning.

Beside: preposition, near, next to, at the side of

I will stand beside you through good times or bad.
She stood beside the fence gate.

Besides: in addition to, apart from, except
It was the most popular book ever written, besides the Bible.
Everyone besides Anna wanted to go swimming.