Adaptive immune cells are specialized components of the immune system that develop a targeted response to specific pathogens, such as bacteria and viruses. These cells include T cells and B cells, which are crucial for recognizing and remembering past infections. When the body encounters a pathogen, adaptive immune cells can quickly identify and eliminate it, providing long-lasting immunity. Unlike the innate immune system, which offers immediate but general protection, adaptive immune cells take time to activate and expand. Once they are trained to recognize a specific pathogen, they can respond more efficiently during future infections, making them essential for the body's defense against diseases.