The Full Form of MDB is‍ Microsoft Business Division.

Microsoft Business Division (“MBD”) develops and markets software and online services designed to increase personal, team, and organization productivity. MBD offerings include the Microsoft Office system (comprising mainly Office, SharePoint, Exchange, Lync, and Office 365), which generates over 90% of MBD revenue, and Microsoft Dynamics business solutions. We evaluate MBD results based upon the nature of the end user in two primary parts: business revenue, which includes Microsoft Office system revenue generated through volume licensing agreements and Microsoft Dynamics revenue; and consumer revenue, which includes revenue from retail packaged product sales and OEM revenue.