Distinct molecules called agglutinogens (a type of antigen) are attached to the surface of red blood cells. There are two different types of agglutinogens, type A and type B. Each type has different properties.
MDB: Geodatabase. The geodatabase is a collection of geographic datasets of various types, with the most basic types being vector, raster, and tabular data. There are three types of geodatabases: file, personal, and ArcSDE. Geodatabases are the native data format for ESRI's ArcGIS.
File and personal geodatabases, which are freely available to all ArcGIS users (i.e., users of ArcView, ArcEditor, and ArcInfo), are designed to support the full information model of the geodatabase. This includes topologies, raster catalogs, network datasets, terrain datasets, address locators, and so on.