Kippot are used differently because people have different customs.
In orthodox communities only men wear kippot and they wear them at all times. In other communities people have the choice to wear kippot. And in some communities women are invited to wear kippot.
Kippot symbolizes that G-D is watching us. This is important to know because this helps people know that G-d is watching us so we do the right thing.
Resources:
https://www.myjewishlearning.com/article/kippah/