[dba-SQLServer] How much storage

How much storage is used for varbinary?  I am looking at using the hash
function of SQL Server (built in to SQL Server 2005 now), and it returns
something like 120-180 "somethings", it is defined as varbinary(8000)
maximum.  AFAICT it is a fixed width that varies depending on the hash
algorithm.  Is it returning an array of characters with 120-180 elements?
Is binary (or varbinary) defined in bits of a 32 bit word?  Is each binary
digit stored as a single position in a character?

John W. Colby
Colby Consulting
www.ColbyConsulting.com