Office 365 Premium is a subscription-based service offered by Microsoft that includes a suite of productivity tools and services for companies with less than 300 employees. It provides access to popular applications such as Word, Excel, PowerPoint, and Outlook, as well as cloud-based services like OneDrive and Skype for Business. Office 365 Premium offers additional features and benefits compared to the basic Office 365 subscription, such as a higher level of storage space, advanced security features, and the ability to install applications on multiple devices for multiple users. It is designed to cater to the needs of both home users and small businesses.