Steam Family Sharing enables you, your friends, and your family to share games with each other while keeping your accounts separate.
With Steam’s easy-to-use feature, you, your friends, and your family can play one another’s games while earning your own achievements and saving your own game progress via the Steam Cloud.
To enable Family Sharing and authorize a shared library, you and whoever you want to share your games with first have to activate Steam Guard.
You can do this by logging into your Steam account on your computer, navigating to Settings, then choosing the Account tab.
Once you’re there, click “Manage Steam Guard account security” and choose either “Get Steam Guard codes from the Steam app on my phone” or “Get Steam Guard codes by email (will require you to re-login).”
After setting up Steam Guard, head back into Settings, navigate to the Family tab, click “Authorize Library Sharing on this computer,” and choose who you want to share your library with. You can select up to five friends or family at a time.
From your Library, you’ll now be able to see games owned by other users linked to your account.
To request access, select a game and simply click “Request Access.” This will send the owner an email with a link that will allow you to play games in their library.