Acquired immunity, also known as adaptive immunity, is a specialized defense mechanism developed by the body in response to specific pathogens or foreign substances. Unlike innate immunity, which provides a general and immediate defense against infections, acquired immunity is highly specific and has the ability to remember previous encounters with pathogens, allowing for a faster and more efficient response in future exposures. This type of immunity is an essential aspect of the human body’s defense system and plays a critical role in maintaining health, preventing infections, and aiding in the effectiveness of vaccinations. Acquired immunity develops over time and is triggered when the immune system identifies antigens, which are foreign molecules present on pathogens such as bacteria, viruses, fungi, or toxins. The detection of these antigens stimulates the activation of specialized white blood cells, including B lymphocytes and T lymphocytes, which are central to adaptive immune responses. Acquired immunity is broadly classified into two main types: humoral immunity and cell-mediated immunity. Humoral