The word interlocking can have multiple meanings in the railway context.
1. This forum is primarily concerned with interlocking as a process by which signalling functions, typically the operation of points (switches) and signals, are prevented from assuming contradictory or unsafe states.
2. The word may also be applied to the piece of equipment that achieves the interlocking process in which case it is an abbreviation for interlocking plant, or interlocking bed, or interlocking machine.
3. Interlocking may also describe an area of railway in which signalling functions are interlocked under some form of centralised control. In this case an interlocking would be distinct from unsignalled or automatically signalled track between locations which are interlocked.