as a noun, 'side' refers to a position to the left or right of an object, location, or point. It can also refer to a particular aspect or facet of something.
The car has a dent on its left side.
Whose side are you on in this debate?
There are always two sides to a story.
'side' can also refer to a dish that accompanies the main course, as in 'side dish.'
as an adjective, 'side' describes something that is supplementary or less important than something else.
The medication may have some side effects.
Use the side entrance when the main door is locked.
He has a side job on weekends.
when 'side' is used as an adjective, it often indicates something secondary or less central than the primary thing.
as a verb, 'side' means to align oneself with a particular party, group, or opinion.
'Side' as a verb is often followed by 'with' to indicate the party, group, or opinion one is aligning with.
I always side with the underdog in any competition.
The judge seemed to side with the prosecution in his remarks.
It's hard to side with anyone in this argument because both have valid points.
'side' as a verb is about taking a position or aligning oneself, not about physical placement.