Acquired immunity is a type of immunity that develops after exposure to specific pathogens, such as viruses or bacteria. This process can occur through natural infection or vaccination. When the body encounters a pathogen, it produces specialized cells and antibodies that recognize and remember the invader, allowing for a faster and more effective response if the same pathogen is encountered again. This immunity can be divided into two main types: humoral immunity, which involves the production of antibodies by B cells, and cell-mediated immunity, which involves T cells that target and destroy infected cells. Acquired immunity is essential for long-term protection against diseases.