Altitude or hicht is defined based on the context in which it is uised (aviation, geometry, geografical survey, sport, an mair). As a general defineetion, altitude is a distance measurement, uisually in the vertical or "up" direction, atween a reference datum an a pynt or object. The reference datum an aa eften varies accordin tae the context. Altho the term altitude is commonly uised tae mean the hicht abuin sea level o a location, in geografie the term elevation is eften preferred for this uisage.
Vertical distance measurements in the "doun" direction are commonly referred tae as depth.