Id also like to mention that fluid pressure is a result of intermolecular forces (bonding, etc), not particle collisions like in gases. By nature of the fluid existing on earth, gravity will pull all the particles down, but they really, really dont want to compress so the bonds are stressed, giving rise to pressure due to gravity. Liquid pressure always behaves like a bunch of ultra strong springs - they compress, but they dont want to. But with all molecules looking in any direction for a way to release the potential energy, hence pressure exists
