Database consistency checker (dbcc) commands lets you check the logical and physical consistency of a database. The dbccdb database stores the results of dbcc checkstorage or dbcc checkverify.
dbcc checkstorage records configuration information for the target database, operation activity, and the results of the operation in the dbccdb database. Stored in the database are dbcc stored procedures for creating and maintaining dbccdb and for generating reports on the results of dbcc checkstorage operations.
See Checking Database Consistency in the System Administration Guide: Volume 2.