**Altitude **is a measurement in distance of a point or object elevated from its foundation. It is measured in vertical direction. Altitude is commonly used in measuring the height of a location above sea level.

Elevation is another term for measuring altitude in the field of geography and astronomy. Determining the angle of a celestial object is measured upwards in astronomical horizon towards the astronomical zenith. The measurement of an object is 0 degrees in altitude on the horizon, and 90 degrees of an overhead altitude from an observerâ€™s view. Objects below the horizon are measured with negative altitudes and -90 degrees for objects in Nadir or anti zenith.

Altitude is used in different aspects such as space, geometry, geography, astronomy, sports and more. Altitude is also used in aviation or in spaceflight. It is measured by using *Mean Sea Level (MSL)* or Above Ground Level (AGL).

Indicated altitude depends on the measurement of the altimeter. Absolute altitude measures the height of an aircraft flying above the terrain and measured in feet or meters Above Ground Level (AGL).

True Altitude measures the object above sea level. Height is an altitude that measures the distance on an object above a certain point. Pressure altitude depends on the air pressure of an altitude. Density altitude is for measuring the density of air.