Microsoft Access Files Extensions - What are microsoftaccess files and how do I open a microsoftaccess file?

What are microsoftaccess files and how do I open a microsoftaccess file?

File Type Category File Format
.accdb Microsoft Access Files Access 2007 Database File
.accde Microsoft Access Files Access Execute Only Database
.mdb Microsoft Access Files Microsoft Access Database
.mde Microsoft Access Files Compiled Access Add-in File