what is a tandem

A tandem is a term used to describe an arrangement where people or animals are in formation, one behind the other. The term is used to describe many things that involve the connecting of one object to another similar object behind it. For example, a tandem tractor-trailer truck has one trailer connected to another trailer behind it. The term is also used to describe a type of bicycle designed for two riders, on which one rider sits behind the other. Tandem kayaks are another example of the term, which are designed for two people to paddle together. The term can also be used to describe a relationship between two persons or things involving cooperative action, mutual dependence, etc.