Politics means the world of government in general:
The vice-president has a long career in politics.
I hate discussing politics with my family because it always turns into an argument.
Sometimes people talk about "office politics" outside the context of government -this means the connections and actions that people inside a company take in order to gain power, forming relationships and manipulating situations to their advantage.
A policy is like a rule. Countries have policies (foreign policy, immigration policy, gun control policy) but schools and companies do, too:
Our policy is that customers can return an item and get a refund within 30 days of their purchase.
My school had strict policies regarding lateness - if you were late more than five times, you got suspended.
A girl finds one of Santas magical reindeer in this cute live action kids film starring Sam Elliott as the gruff, grieving father of eight year old Jessica (Rebecca Harrell), whos obsessed with Christmas. Jessicas optimism will teach the town a thing or two about the true spirit of the season.