What is true altitude?

True altitude is the actual height above sea level at which an object is located. It is often used in aviation to determine the actual height of an aircraft above the Earth's surface. True altitude is different from indicated altitude, which is the altitude shown on an altimeter, as it takes into account factors such as temperature, pressure, and other atmospheric conditions that can affect the accuracy of the altimeter reading. True altitude is important for navigation and safety, as it helps pilots and air traffic controllers ensure that aircraft are flying at the correct altitude to avoid collisions and other hazards.