What is Specific defence mechanism

Specific:  These relate to specialized cells located throughout the  body which respond to invasion of foreign materials/microorganisms  such as bacteria, virus, fungi or  unwanted substances produced or entering  the  body. Some specific cells are  fixed  in  tissues such as thymus, lymph nodes, bone marrow, spleen, lymphoid  tissue of the respiratory, gastrointestinal and genitourinary  tract, kupffer cells of  the liver and Peyer's patches of  the small intestine.