Memory T Cells are a type of immune cell that play a crucial role in the body's defense against infections. After the body encounters a pathogen, such as a virus or bacteria, some T Cells become memory cells. These cells remain in the body long after the infection has cleared, allowing for a quicker and more effective response if the same pathogen is encountered again. When Memory T Cells recognize a previously encountered pathogen, they rapidly multiply and activate the immune response. This ability to "remember" past infections helps the body respond more efficiently, often preventing illness or reducing its severity. This is why vaccines, which stimulate the production of memory cells, are so effective in providing long-term protection.