A liquid in equilibrium has a fundamental properties that it exerts a force on any surface in contact with it and this force act perpendicular to the surface.
![Thrust](https://mrmanojpandey.com/wp-content/uploads/2023/11/Thrust-1.jpg)
The total force exerted by a liquid on any surface in contact with it is called thrust. It is because of this thrust that a liquid flows out through the holes of the containing vessel.
As thrust is a force, so its SI unit is Newton(N).