what 'multi-part identifier' since can't bound?

i continuously errors i try transform tables formed another table. i finish adult rewriting query, change method joins, change groupings following eventually works, nonetheless i only don't definitely it.

what 'multi-part identifier'?

when 'multi-part identifier' means bound?

what being organization anyway?

in cases blunder occur?

what best ways hinder it?

the specific blunder sql server 2005 is:

the multi-part identifier "..." bound.

here an example:

update  [test].[dbo].[companydetail]

set mnemonic = [dbbwkmigration].[dbo].[company].[mnemonic], 
               [company code] = [dbbwkmigration].[dbo].[company].[companycode]

where [company name] = **[dbbwkmigration].[dbo].[company].[companyname]**

the tangible error:

msg 4104, turn 16, state 1, line 3 multi-part identifier
"dbbwkmigration.dbo.company.companyname" bound.