<prompt> Answer this question truthfullyWhat does the term affinity mean when referring to an antibody and its interaction with an epitope?  <response>: <reason> Antibodies are proteins produced by the immune system in response to foreign substances, such as viruses or bacteria. When an antibody encounters a specific target, called an epitope, it binds to it with a certain strength or affinity. The affinity of an antibody refers to the binding strength between the antibody and the epitope. A high affinity antibody binds strongly to its target, while a low affinity antibody binds more weakly. Affinity is an important characteristic of antibodies, as it affects their ability to recognize and neutralize foreign substances in the body. 