The CGA (Controller General of Accounts) works under the Ministry of Finance and is responsible for prescribing the form of accounts and maintaining accounting systems for civilian ministries. The CAG (Comptroller and Auditor General) is a Constitutional authority responsible for auditing government accounts. The CGA prepares accounts; the CAG audits them. The CGA acts on the advice of the CAG when prescribing account forms.
Source: GAR Rule 1