Access is a rapid application development system for creating powerful databases to work hand in hand with the Office suite of programmes.
Access hosts a powerful query and reporting package which gives the user speed and simplicity in creating queries and reports to meet ad-hoc reporting needs.
Latterly, Microsoft have brought out a variant of Excel called Power Pivot.. This links into Access and SQL Server to allow the creation business intelligence data from millions of records in very short response times.
The drawback with Access has been its lack of adaptability to the Web. That has all changed now with the advent of Office 365 and SharePoint Services. These two application have brought about a renaisance for MS Access as a viable web database (albeit, much changed).