It is like a switchboard in an electrical circuit because it lets the operator control how much fluid flows between which components of a hydraulic machinery.
[1] A manifold is composed of assorted hydraulic valves connected to each other.
It is the various combinations of states of these valves that allow complex control behaviour in a manifold.
[1][citation needed] A hydraulic manifold is a block of metal with flow paths drilled through it, connecting various ports.
[2] Hydraulic manifolds consist of one or more relative large pipes called a "barrel" or "main", with numerous junctions connecting smaller pipes and ports.