How is the word their generally used in a sentence?

There are three different variations of the Word. The Word "there" can be used to describe a location. An example sentence would be: "Sally went there to buy milk." The Word "they're" means "they are." An example sentence for this would be: "Tim and Jane can be so annoying, but they're still my friends." Finally, the Word "their" shows possession of an item or object. An example sentence would be: "They went to their house after school." An example sentence using all three in the same sentence would be "They're going there to pick up their medications."