The answer to this question is that antibodies are proteins in nature and these proteins are manufactured by B cells and also discharged by them. The intellectual meaning of “antigen” implies to their activity, and this activity is characterized by the bound between an antigen and an antibody. It is also called Immunoglobulin (Ig). These molecules are found to be in Y shape and they contain a pair of heavy and light chain respectively. As antibodies contain the Y shape the antigen comes and attaches to the top of that Y shaped portion of the molecule. The most characteristic significance of an antibody is that it has the ability to identify a particular antigen and this happens because of such clear-cut binding sites. A diagram of such antibody is given below.