Both insurance and bond are important concepts in the CDS exam.

There are actually 5 major difference between these two, as explained in this website:

http://www.yutzmerkle.com/2012/05/04/5-key-differences-between-insurance-and-surety-bonds/

For me difference no. 3 is easiest to comprehend- insurance is protection against damages, while bond is a guarantee of fulfillment of obligations.