The word change means for something to become different. The word switch is more specific - it means to stop using/doing one thing and start using/doing another.
I'm going to change a few things in my life this year.
Could you switch seats with me, so I can sit next to my husband?
(the two people will exchange seats)
Her personality has changed a lot recently.
I wasn't happy with my Nokia cell phone, so I switched to a Samsung. (I stopped using the Nokia and started using the Samsung)