Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Your account at https://account.microsoft.com/services should tell you what you are paying for. Note that you may have more than one account. Hypothetically, each of your @outlook.com and @hotmail.com accounts is its own Microsoft account (a third-party e-mail such as @gmail.com can also be a Microsoft account alias).
For more, see https://support.microsoft.com/en-us/accounts-billing/how-to-investigate-a-billing-charge-from-microsoft.