Altitude, like elevation, is the distance above sea level. Areas are often considered "high-altitude" if they reach at least 2,400 meters (8,000 feet) into the atmosphere. ... This is called indicated altitude, and is measured by an instrument called an altimeter. As altitude rises, air pressure drops.
the height of an object or point in relation to sea level or ground level.
Explanation:
height above sea level
Although the term altitude is commonly used to mean the height above sea level of a location, in geography the term elevation is often preferred for this usage. Vertical distance measurements in the "down" direction are commonly referred to as depth.
