There are a few things you should keep in mind before sharing your library on Steam. Since it’s not possible to share only some games and exclude others, your entire library will be accessible to authorized users. In addition, the number of authorizable accounts is limited to a maximum of five, and your Steam Family Library can be used on a maximum of ten different computers. Also, sharing your Steam library doesn’t mean that you and your friends or family members can play at the same time. Only one user can access the library at a time, but as the main account, you will always have access.
So, if you want to play, the other person will first be forewarned, and their game will then be interrupted after a short time. If the current game hasn’t been saved by then, the progress will be lost. Region-restricted content cannot be shared into different territories. So, in case of doubt, the authorized accounts are subject to the restrictions of your region as the main account. In the worst-case scenario, if an account you’ve shared is caught cheating, this can also affect your access. And on top of everything else, games that require a third-party subscription or are free cannot be shared via Steam Family Sharing.