A Coordinate is a location on a graph, denoted by a
point. In order to describe where something is in Roblox you need to have 3 coordinates, one for the X-axis, one for the Y-axis, and one for the Z-axis.
These are normally arranged into a
Vector, a combination of an X, Y and Z coordinate.
You can see this by putting into the Command Bar.
print(Vector3.new(1, 2, 3))
This results in:
1 2 3
Which is the Vector of the coordinate.