Data Format Explanations

Definitions are from ESRI's Online Help:
  • Geodatabase - An ArcGIS geodatabase is a collection of geographic datasets of various types held in a common file system folder, a Microsoft Access database, or a multiuser relational database (such as Oracle, Microsoft SQL Server, or IBM DB2). Versions 8.3, 9.1, 9.2, 9.3 are available.
  • Shapefile - Shapefiles are a simple, nontopological format for storing the geometric location and attribute information of geographic features. Geographic features in a shapefile can be represented by points, lines, or polygons (areas). The workspace may also contain dBASE tables, which can store additional attributes that can be joined to a shapefile's features.

    Shapefiles can be read by most GIS software programs and most newer CAD software programs.
How to Open Shapefiles in Autodesk AutoCAD
Type: mapimport in the command line. That opens the Import Location window. Select ESRI Shapefile from the drop down list and then browse to the location of your shapefile.
Example of how to open shapefiles in Autodesk AutoCAD