What is hydrostatic pressure?

Hydrostatic pressure refers to the pressure exerted by a fluid at equilibrium due to the force of gravity. In the context of the question, it specifically denotes the weight of water acting on a given surface. This concept is critical in fields like engineering and physics, as it helps to understand how fluids behave under the influence of gravity.

When considering hydrostatic pressure, it is essential to recognize that as the depth of the fluid increases, so does the pressure due to the increasing weight of the fluid above. This principle is foundational in applications like water tanks, dams, and other systems where liquids are involved, as it affects the design and safety of these structures.

The other options describe different types of pressure but do not pertain directly to the concept of hydrostatic pressure. While the pressure exerted by gas in a boiler, the pressure created by steam, and the pressure changes during operations like drain cycles are all relevant in the context of boiler operation and fluid dynamics, they are not indicative of the specific characteristics that define hydrostatic pressure.