VST file extension

Microsoft Visio is a diagram application that creates diagrams using vector graphics. It is distributed as part of the Microsoft Office Family and is also available as a subscription through Microsoft Office 365. 

Visio allows users to create professional diagrams with just a few clicks. It makes diagramming simple, whether you want to capture a flowchart that you brainstormed on a whiteboard quickly, map an IT network, build an organizational chart, document a business process, or draw a floor plan.

Microsoft Visio 2010: Visio Viewer is used to view drawings and diagrams created in Microsoft Visio (Visio 5.0 - Visio 2010) in the Microsoft Internet Explorer.

Microsoft Office is popular productivity suite for Microsoft Windows. Microsoft Office contains a set of applications and services used to work with documents (Microsoft Word), spreadsheets (Microsoft Excel), presentations (Microsoft PowerPoint), databases (Microsoft Access) etc..

Microsoft Office can be also used to manage e-mail accounts, tasks, calendars and contacts (Microsoft Outlook). 

Office 365 is a subscription-based service that gives users access to several services and apps from Microsoft Office. It is available for some types of subscription editions (Home, Education, Business, and Enterprise users) for Microsoft Windows, Apple macOS, and all major mobile platforms.

Office 365 service was replaced by Microsoft 365 subscription service.