Steam is an online service offered by Valve.
You become a subscriber of Steam ("Subscriber") by completing the registration of a Steam user account. This Agreement takes effect as soon as you indicate your acceptance of these terms. You may not become a subscriber if you are under the age of 13. Steam is not intended for children under 13 and Valve will not knowingly collect personal information from children under the age of 13.
A. Contracting Party
For any interaction with Steam your contractual relationship is with Valve. Except as otherwise indicated at the time of the transaction (such as in the case of purchases from another Subscriber in a Subscription Marketplace), any transactions for Subscriptions (as defined below) you make on Steam are being made from Valve.
B. Subscriptions; Content and Services
As a Subscriber you may obtain access to certain services, software and content available to Subscribers. The Steam client software and any other software, content, and updates you download or access via Steam, including but not limited to Valve or third-party video games and in-game content, (...)