Antibodies ( also known as immunoglobulins) are Y shaped proteins designed to stop antigens (basically just unwanted visitors) from entering our bodies. They do this by finding and labeling the antigens. Which lets the body destroy them. However each antibody is made for one and only one antigen, and it’s fitted with special receptors that will only bind to that antigen.
When an antigen tries to enter our body, it is first met by a type of cell called a B cell which is responsible for creating antibodies to match the antigen. After this the antibodies stick to the virus they order the T cells to kill the virus-infected cells. after this a wave of phagocytes come and eat all of the foreign matter left behind.
After an infection is defeated once, the next time it tries to infect you your body will use the same antibodies it used the first time to combat the infection a lot quicker. This is called acquired immunity.
Another way your body helps combat infections is through the use of white blood cells ( Leukocytes ) which flow through your body in your blood streams and produce antibodies to destroy pathogens, and antitoxins to neutralise toxins.