Connectors are devices used to connect a fibre-optic cable to an optical fibre device, such as a detector, optical amplifier, optical light power meter, or link to another fibre cable. The key to a fibre-optic interconnection is precise alignment of the mated fibre cable cores so that the light couples from one fibre, across the junction, into the other fibre. This chapter presents the operating principles of the connectors and splices, and describes their types, properties, and operations. It provides several experimental cases for building a connection between two fibre-optic cables; linking two fibre cables by connectors and a fusion splice; and testing the connection for losses. Fibre connectors are designed to be easily connected and disconnected. Fibre-optic cable can be easily connected to a transmitter, receiver, power meters, or another fibre cable. Fibre connectors designed for indoor applications must be protected from environmental extremes to avoid excessive connector loss and poor system performance.