Call and response is sometimes described as a "question and answer" style. It is found in almost all styles of music and originally comes from African music, and the Blues. In Gospel music, the "call" is made by the preacher and the "response" is made by the congregation.
The simplest form of call and response is direct imitation. The following example gives you an opportunity to practice responding to a phrase by ear. It is not notated, but there is a space after each phrase so you can respond to what you have just heard.