"There" vs. "Their" vs "They're"

Which one should you use?

Their

Their is used to indicate possession.

Example: "That is their group project."

There

There is used to indicate direction or location.

Example: "There is no more milk in the fridge."

They're

They're is a contraction of the two words "They" and "Are", so you can use it when you want to contract the two words.

Example: "They're visiting their grandmother in California.