This article describes DBF files, including how to open them and how to save them in another format such as CSV, XLS, etc.
A file with the .DBF extension is most likely a database file used by the dBASE data management system. Data is stored in the file in an array of multiple records and fields.
Because the file structure is quite simple and the format was used in the early days of database programs, it is considered a standard format for structured data.
Esri's ArcInfo also stores data in files ending in .DBF, but it's called the shapefile attribute format instead. These files use the dBASE format to store attributes for shapes.