Okay so I already asked a bit about this, but I think I'm gonna need to post several questions on this to understand it, so here goes: I understand the definition of pressure, just not how it is applied to fluids. How is pressure in a fluid to be interpreted. Is it the force that the particles that make up the fluid exert on an area in the fluid? I think that is correctly understand, but then I just don't understand why the pressure gets bigger the farther you are down a fluid. Why would the total force that the nearby particles exert on your area (we could imagine a thin disk in the fluid) depend on how many particles that are above you? And further I don't even get how you can say things like this (which my book often does): Every little cube inside the fluid is at rest etc etc. Indeed the fluid is never at rest since, the particles that make it up are whirling around! What am I getting wrong?