Tissue culture refers to a technique used in biology and agriculture where living cells are isolated from an organism, grown in vitro (in a controlled environment), and maintained for various purposes such as research or commercial production. It involves the use of specialized media and equipment to support growth and development of plant or animal tissues, organs, or cells under sterile conditions. The process can be used for many applications including plant propagation, studying cell function, producing biological products (such as vaccines), and conducting research on various organisms.