Venkata Prasada Rao Thalla

The Fixed joint  is all 6 degrees of freedom are fixed, all three translations and three rotations.

Contacts are different category, in that contact is between two different types of regions with different properties.

Bonded contact is to just to transmit loading/displacments from one side to another side of joint, such that loads/displacments are transmitted through, specially without any node sharing or meshing at the joint. Bonding allows us to have different mesh types/mesh quality on eighter side of the joint.