Definition
Coordinate
A coordinate is one number that tells a point's position along a chosen axis.
What it means
Think of a point's address. On a flat grid, the first coordinate tells how far to move horizontally and the second tells how far to move vertically. The order matters because each number belongs to a different axis.
Remember it
A point's address has a fixed order: across first, then up or down.
Example
For P = (−2, 3), the x-coordinate is −2, so move 2 units left from the origin. The y-coordinate is 3, so move 3 units up. Those two coordinates locate P.
Watch for
A coordinate is one number, while an ordered pair contains two coordinates for a point in a two-dimensional plane.
Common mix-up
Swapping the coordinates usually gives a different point: (2, 5) is not the same as (5, 2).
Exact meaning
A coordinate is one number in a coordinate system that specifies a point's position relative to an axis or reference direction. In a two-dimensional ordered pair (x, y), x and y are the two coordinates.