A collect call, also called a "reverse charge call", is a type of telephone call. Usually, when a telephone call is made, the person who makes the call pays for the call, rather than the person who receives the call at the other end. In a collect call, though, the person making the call wants the person they are calling to pay for the call instead.
In the past, these kinds of calls could only be done with a operator, who would need to ask the person receiving the call if they want to be charged for it. If the person receiving it does not want to be charged, the call cannot go through. Today, computers have made it possible to make or receive collect calls without talking to a person.