A waypoint is a reference point that helps us know where we are and where we're going. Whether we are walking, driving, sailing, or flying, waypoints help us find our way. 
 
For centuries, waypoints were landmarks: rock formations, springs, mountains, and roads, for example. Physical landmarks are still used as waypoints today. Landmarks used as waypoints can be natural, such as a tree. They can also be manmade, such as a billboard. 
 
Waypoints can also be physical things that hold navigation devices: buoys in the ocean or satellites in the sky, for example. These types of waypoints are used for collecting data. An ocean buoy can transmit information about water temperature, salinity, and chemical properties at that waypoint.
 
Coordinates
 
Coordinates are some of the most familiar and reliable of waypoints. Coordinates include degrees of longitude and latitude. Lines of longitude are imaginary lines running north-south on the globe. Lines of latitude are imaginary circles (called parallels) that run around the world from east to west. 
 
Every spot on Earth can be located with the waypoints of longitude and latitude. Coordinates are used not only by navigators, but also by scientists and engineers. Wildlife biologists use coordinates to track the migration of animals, for example. Engineers use coordinates and other waypoints to plan the best place for a building or a park. Waypoints can also be used to document the movement of tides, currents, and erosion patterns.
 
GPS Waypoints
 
Satellites in the sky are part of the global positioning system (GPS). Satellites tell devices like smartphones and car navigators how travelers can get where they're going. 
 
As people depend more on GPS to set them on the right paths, waypoints are becoming less tied to physical landmarks like mountains and rock formations. GPS waypoints are much more specific: They identify an exact spot on Earth.
 
Waypoints in the atmosphere or outer space usually include altitude. These waypoints let pilots know how tall a mountain is, for example.
 
GPS and other navigation systems will often combine waypoints. A specific set of coordinates is presented with a physical landmark to help orient the user.
 
GPS allows users to create waypoints, as well as use ones already in existence. Users identify and mark waypoints on base maps, and can identify more than one to create a route
 
RNAV Waypoints
 
Area navigation (RNAV) is a method used by aviators to fly between a network of navigation beacons. RNAV uses fly-over waypoints and fly-by waypoints to indicate where pilots can safely make turns. 
 
As its name implies, pilots must fly directly over a fly-over waypoint
 
Fly-by waypoints, usually indicated by a four-pointed star, are much more common. Pilots can take a "short cut" and turn ahead of the fly-by waypoint.
 
waypoint
A waypoint helps tell you where you are, not necessarily where to go or how to get there.

In Transit
GPS navigation began to be widely used by people and businesses during the 1990s. However, the technology is not new. Transit, a satellite navigation system used by the United States military, passed its first successful test in 1960.

Noun

the distance above sea level.

Noun

layers of gases surrounding a planet or other celestial body.

buoy
Noun

floating object anchored to the bottom of a body of water. Buoys are often equipped with signals.

chemical property
Noun

unique identity of a substance expressed by its type and arrangement of molecules.

coordinates
Noun

a set of numbers giving the precise location of a point, often its latitude and longitude.

data
Plural Noun

(singular: datum) information collected during a scientific study.

engineer
Noun

person who plans the building of things, such as structures (construction engineer) or substances (chemical engineer).

Noun

act in which earth is worn away, often by water, wind, or ice.

fly-by waypoint
Noun

location near where a pilot is required to fly, but where a pilot turns in anticipation of the location.

fly-over waypoint
Noun

location over which a pilot is required to fly.

Global Positioning System (GPS)
Noun

system of satellites and receiving devices used to determine the location of something on Earth.

landmark
Noun

a prominent feature that guides in navigation or marks a site.

Noun

distance north or south of the Equator, measured in degrees.

Noun

distance east or west of the prime meridian, measured in degrees.

Noun

movement of a group of people or animals from one place to another.

mountain
Noun

landmass that forms as tectonic plates interact with each other.

navigation device
Noun

instrument, such as a compass, used to locate direction and place.

orient
Verb

to position or find the location of something.

parallel
Noun

line of latitude, dividing the Earth by east-west.

pilot
Noun

person who steers a ship or aircraft.

reference
Noun

source of information or direction.

RNAV
adjective, noun

navigation method that allows an aircraft to choose any course within a network of navigation beacons. Also called area navigation or (originally) random navigation.

road
Noun

path, usually paved, for vehicles to travel.

rock
Noun

natural substance composed of solid mineral matter.

route
Noun

path or way.

salinity
Noun

saltiness.

satellite
Noun

object that orbits around something else. Satellites can be natural, like moons, or artificial.

smartphone
Noun

mobile telephone with additional features, such as a web browser or music playing device.

spring
Noun

small flow of water flowing naturally from an underground water source.

Noun

degree of hotness or coldness measured by a thermometer with a numerical scale.

Noun

rise and fall of the ocean's waters, caused by the gravitational pull of the moon and sun.

transmit
Verb

to pass along information or communicate.

Noun

a set of GPS coordinates used for navigation.

wildlife biologist
Noun

person who studies animals in their native habitats.