Antibody specificity refers to the process of each individual antibody being able to bind to only one unique epitope on the antigen binding site. More specifically, the antigen binding site is found between variable regions of light and heavy chains. This region is known as the antigen-binding fragment (Fab), which allows for the recognition of a wide range of antigens. The Fab is composed of 6 hypervariable CDR regions which make up the large surface for antigen recognition. 

Antibody specificity permits the precise identification of a target antigen, while avoiding the detection of antigens not of interest. This mechanism is vital for the body's immune system to distinguish between pathogens and normal cells. When a pathogen invades the body, the immune system produces antibodies which are unique to the epitope of that antigen.