I need a quick summary of the immune system, it's function and why it is so important for the body. Thanks.

Immune system is responsible to fight against foreign invaders from affecting the body system,immune system acts as a security against any offence microorganisms from have access to the body, thereby prevent illness. It is so important to have functioning immune system for an individual to be healthy, for example HIV destroys the immune system, therefore making it possible for a lot of diseases crept in

the immune system is very important that resist and protect the body from foreign bodies ( bacteria and viruses)

Explanation:

it is so important because it is the body resistance for our bodies

if it in not available we will face diseases