Directional Valve Animation Of 2 Way / 2 Position Explanation:

There are two P1 and P2 oil ports of the valve, the spool on the left side when the valve does not work, the spool seals the two of P1 and P2 oil ports.

The spools moves to right side when there is a force pushing the spool, the oil is exertedfrom the P1 ports to P2 ports gradually until the spool at the end of the right side. – finotek.com

Directional Control Valve Animation:

Directional Valve Animation Of 4 Way / 2 Position Explanation:

There are A, B, O, P oil ports on the bottom of directional valve, the O, P is outlet ports and A, B is inlet ports. The A ports connects O and B connects P port when the spool is on the left side.
The A port is beginning to connect P port, and B to T port while the force is pushing the spool to right side, the oil porting will be through completely until the spool at the end of the right side. – finotek.com

Directional Control Valve Animation: