What does Pascal's principle state about pressure in confined fluids?

Pascal's principle, named after Blaise Pascal, asserts that when pressure is applied to a confined fluid, that pressure change is transmitted undiminished to every point in the fluid. This means that any increase in pressure at one point in the fluid is felt equally in all directions throughout the entire volume of the fluid. This concept is foundational to many applications in fluid mechanics, such as hydraulics, where it enables the use of a small force applied over a small area to generate a much larger force over a larger area, exemplified by hydraulic systems.

The other options do not accurately describe Pascal's principle. While the pressure in a fluid can decrease with depth, this pertains more to hydrostatic pressure rather than the principle itself. The notion of pressure remaining constant at all points is misleading, as pressure can vary depending on external forces or changes in height within the fluid. Lastly, the statement connecting pressure with the weight of the fluid does not encompass the essence of Pascal's principle, which is specifically about the transmission of applied pressure.