Explanation/Reference:
Explanation:
Contracts define inbound and outbound permit, deny, and QoS rules and policies such as redirect.
Contracts allow both simple and complex definition of the way that an EPG communicates with other EPGs, depending on the requirements of the environment. Although contracts are enforced between EPGs, they are connected to EPGs using provider-consumer relationships. Essentially, one EPG provides a contract, and other EPGs consume that contract.
Reference: http://www.cisco.com/en/US/prod/collateral/netmgtsw/ps13004/ps13460/white-paper-c11-
729906_ns1261_Networking_Solutions_White_Paper.html