What is the difference between fan-in and fan-out? Examples

Fan-in refers to the maximum number of input signals that feed the input equations of a logic cell. Fan-in is a term that defines the maximum number of digital inputs that a single logic gate can accept. Most transistor-transistor logic ( TTL ) gates have one or two inputs, although some have more than two. A typical logic gate has a fan-in of 1 or 2.