You may login in to services like OneDrive, Xbox LIVE, and Outlook.com using your Microsoft account, which consists of your email address and password.
You can log into your existing Microsoft account or make a new one if you utilise any of these services.
Study up on Microsoft accounts.
You will be required to log in with a Microsoft account in order to sign up for a trial or purchase Microsoft 365.
Installing and managing your Microsoft 365 membership as well as using some subscription features, such as cloud storage, require that you are logged in with this account.