Definition
A pair of angular measurements that identify a precise point on the Earth's surface. Latitude measures how far north or south of the equator the point lies, expressed from 0° at the equator to 90° at each pole. Longitude measures how far east or west of the Prime Meridian (which runs through Greenwich, England) the point lies, expressed from 0° to 180° in each direction. Together, the two values pinpoint any location on the globe and are typically given in degrees, minutes, and seconds, or in degrees and decimal minutes.
Plain English
Two numbers that together name an exact spot on Earth — one tells you how far north or south you are, the other tells you how far east or west.
Context Anchor
Seen in airport information, charts, navigation systems, and airport data pages when an exact location must be identified.
Derivation
Latitude comes from the Latin latitudo meaning 'breadth' or 'width' — the sideways spread of the Earth from the equator. Longitude comes from the Latin longitudo meaning 'length' — the long way around the globe from east to west. The names reflect how early mapmakers thought of the Earth: wide bands running across (latitude) and long lines running around (longitude).
Why Pilots Care
They give an exact, universal way to identify airports, waypoints, and emergency landing sites without relying on names or radio aids.
Analogy
Like the row and seat numbers on a ticket — one number narrows you to a row, the other to a specific seat. Together they identify exactly one place.
Intuition Check
Lat/long coordinates are not a heading to fly or a distance from your airplane. They describe where a fixed point is located on Earth.
Example Sentence 1
The pilot entered the airport's lat/long coordinates into the GPS to create a direct-to waypoint.
Example Sentence 2
When the destination was not in the database, the crew used the published lat/long coordinates to program the approach.