What is a Steam gift purchase?
When you purchase a game on Steam, we offer the option to “gift” the item to anyone you choose, whether or not the recipient is a current Steam user. The recipient will receive the gift as an attractive e-mail card with a personal message from you and instructions to redeem the game.
A Steam gift purchase is a one-time transfer—after the recipient has activated and installed the game, it is a non-refundable game in his or her Steam games collection. Also note that you may only gift new purchases—you may not transfer games you already own. That’d be like wrapping up and presenting the toaster you’ve used every morning for the past year.
How can I purchase Steam Gifts for a different Steam user?
To give a gift to a friend or family member, locate the game you would like to gift on the Steam Storefront and then click the "purchase" button. As you are reviewing your order, you will see a notice that asks "Is this a gift?". Click the check box next to "Yes, it's a gift" and hit "next". If the Steam account you are making the purchase on already has a subscription to the game that you are attempting to gift, it will default to a gift purchase.