A DBH is a convenient way to associate keys composed by characters to data
records. Any kind of digital information can go into the data record, such
as text, graphic information, database structures, you name it. The idea
behind using a DBH is to get rid of what is known as an index file in the
database world. In the DBH world, the index is built into the file format.

WWW: http://www.gnu.org/software/libdbh/