Today we are going to learn to use the there/they’re & their in the correct places.

Do not confuse there, their, and they’re. That would be a serious mistake.

They’re is short for they are.
Their shows possession. It’s just like my, his, her, and our.
There is a place. It’s similar to here.

http://www.grammar-monster.com/easily_confused/there_their_theyre.htm