A Steam Account, or just Account, is Steam's user accounting process, used to access Steam software and most Steam features. An Account is tied with a Steam Profile and vice versa, although the latter is not required to hold an account.
Users must create an account to buy and use software, access the Steam software page, join communities, add and talk to friends, among other features. Steam Accounts are created using an email, and may also be secured using Steam Guard.
Creating an Account
Users may create an account by going to the main Steam homepage and clicking the "Login" button at the top, or by running the Steam software and clicking "Create an Account". Users will be prompted to enter their username, email and/or phone number, and enter their password twice. The email will then be verified and the account will be created. Only one account may be created per email; for example, the email "firstname.lastname@example.org" may not be registered to two accounts at once.
An account is required to purchase and use any Steam software, and to access the Steam software. A user attempting to purchase software without an account will be prompted to login or create an account. Users with an account may also customize their Steam Profile and distinguish them from other users. Multiple users may have the same username; however, users are able to be separately profiled by their unique SteamID.
Upon creating an account, Steam will automatically apply restrictions to the account known as an "Account Limit". This is to prevent spamming, phishing and other abuse by botted accounts. Accounts that are limited may not add friends, request group access, open a group chat, vote on a review or Workshop item, add or purchase items from the Community Market, participate in trading, post frequently in discussions posts, gain Profile Levels or trading cards, submit content on the Workshop, access the Steam Web API, use browser or mobile chat, add public artwork or screenshots, add messages to trade offers, create Steam groups and/or follow/add a curator.
An account limit is automatically lifted upon spending $5.00 USD or more to add funds onto users' Steam Wallet, purchase software worth $5.00 USD or greater on the Steam Store, adding a Steam Wallet card worth $5.00 USD or greater and/or purchasing a Steam gift equal to $5.00 USD or more, although receiving a gift does not count. Each purchase counting toward lifting the limit is counted in USD, and if the user's currency is not USD, it will automatically be converted to count toward the lift.
Activating a retail game, playing a free demo, adding a non-Steam game shortcut, spending Wallet funds gained from the Market, adding/playing a promotional free trial of a software, activating a Free to Play game and/or activating a promotional CD Key will not lift the account limit.