What does "Received: fromoutbound.protection.outlook.com" mean?

Noticed a lot of outlook type of message in the headers of the email.

Eg
Received: from NAM02-BN1-obe.outbound.protection.outlook.com (mail-bn1nam07on2083.outbound.protection.outlook.com. [40.107.212.83])

What exactly does that mean? It's sent using a Office 365 account?