Multicore cable
A multicore cable is a type of electrical cable that combines multiple signals or power feeds into a single jacketed cable. The term is normally only used in relation to a cable that has more cores than commonly encountered. Not all cables with multiple insulated conductors are called multicore cablesthe "core" in "multicore" refers to the number of usable connections made, not the number of conductors or wires. In most cases, a "usable connection" requires multiple conductors, such as the positive and negative conductors used for DC power. For example, a standard three-conductor mains cable is never  referred to as multicore, but a cable comprising four coaxial cables in a single sheath would be considered multicore. Confusingly, the term "multicore" is occasionally used to refer to the number of individual conductors rather than the number of connections, especially in Europe. A cable with multiple conductors, but not a multicore cable, is usually called a "multi-conductor" or "multi-wire" cable. Construction. By definition, multicore cables have an outer sheath which surrounds all of the inner conductors. This is usually in the form of an extruded PVC or cross-linked polyethylene jacket, often combined with an aluminium sheath  under the surface for electromagnetic shielding. In many applications, this jacket adds significant mechanical protection, making the cable much more rugged. Sometimes each individual connection or "channel" also has its own jacket to aid mechanical or electromagnetic protection. Some multicore cables terminate in a multipin connector, often circular. Others split the cores into separate cables at the ends, terminating in a mass of connectors. This type of end is often called a "fan" or "tail". Applications. Multicore cables can be used for analog and digital signals as well as power distribution. They are often used to simplify the physical setup  of a system and provide a neater connection between two pieces of equipment. For example, in sound reinforcement, a multicore cable is often used to connect all the microphones on stage to the mixing console. This is much easier than running many individual cables, which can become messy and time consuming. Some multicore cables combine different types of connections, such as a "siamese cable" which typically consists of power and coaxial conductors. This type of multicore is often advantageous in home wiring as it minimizes the number of cables run through the subfloor or ceiling cavity of a building. Some  common applications of multicore cables are: