Microsoft Exchange is a mail server and calendaring server developed by Microsoft. It is primarily used for managing emails, calendars, contacts, and tasks within organizations. Exchange allows users to send and receive emails, schedule meetings, and share information seamlessly across different devices. The platform supports various features such as email filtering, security protocols, and integration with other Microsoft products like Outlook. It can be deployed on-premises or accessed through the cloud via Microsoft 365, providing flexibility for businesses of all sizes to manage their communication and collaboration needs effectively.