The word “side” has other meanings, too
People on your mother’s side of the family are your mother’s relatives:
My mother’s side of the family all come from Texas. A side can also be a team in sport:
The German side played very badly in the match. If you are on someone’s side, you support that person:
Don’t be angry. I’m on your side. I’m trying to help you. If you take sides, you support one group against another: I don’t want to take sides in the argument between you and your sister, but you get very heated. You can also talk about a side to someone’s character or personality. People may, therefore, have a generous side, an ambitious side or a romantic side: He always seems very practical, but he does have a romantic side, too.