CIBIL stands for Credit Information Bureau (India) Limited. 

It is one of the 4 credit bureaus that compute credit scores in India. The other three are:
Equifax, Experian, and CRIF Highmark. 

CIBIL Score is a three-digit numeric summary of your credit history. The score is derived using the credit history found in the CIBIL Report (also known as CIR i.e Credit Information Report). A CIR is an individual's credit payment history across loan types and credit institutions over a period of time. 

A score above 700 is generally considered good.

Source: CIBIL FAQs