In english we use apostrophe s or 's to show ownership of something for the most part there are other things we use an apostrophe s for, but in this certain situation it is used to show ownership
For Example. One's emotion, the emotion of that one person
Kate's dog. The dog belongs to Kate
Now the s apotrophe or s' is used to show ownership also, but it is for multiple people or things
Ex: The two boys' hats.
The Sanchezes' house ( Sanchez, sanchezes plural a last name)
Hope it helps