Is a CRB a police check?

In a word, no! The term ‘police check’ is now obsolete in the UK. Many people will still use such terminology but the actual word is ‘Disclosure’.
 
You are still able to obtain information from the police under the public assess route using the Data Protection Act 1998 legislation. However, this is not acceptable for employment purposes, as it does not cover legislation under the Rehabilitation of offenders Act 1974 (Exceptions Order) or Part V of the Police Act 1997.
 
These Acts were revised in the year 2000 and cover areas of access never before allowed to organisations employing persons in positions of trust. The most important aspect of Disclosure is the protection of children and vulnerable adults where only an Enhanced Disclosure will suffice.