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.
On average, women apply some 200 chemicals to their skin each day. Yet 99 percent of mass-market skincare products contain preservatives shown to have genderbending effects on mammals; while other chemicals used are known carcinogens or can have neurological effects. Items branded as antiaging are not usually the most natural choice. Green up your makeup bag and beauty routines to avoid suspect items.