A Built-in or Fixed or Encastre Support:

It is a support which restrains complete movement of the beam both in position as well as direction. The support gives all of the three relevant reactions (say R_x, R_y and M_z), that means the reactions in x and y directions and fixing moment M_z. In other terms, the fixed support offers resistance against translation in both the directions and also against the rotation.

                    M_A - Fixing Moment at the Support 'A'

Figure: A Built-in or Fixed or Encastre Support