Vector field
Also called Vector field map, Field map
A vector field attaches a vector to every point in a region of space, so each location carries both a magnitude and a direction. Gravitational, electric and magnetic fields are vector fields, and AP draws them as vector field maps.
A field turns a force into a property of space. AP Physics 1 EK 2.6.A.2: a field models the effects of a noncontact force exerted on an object at various positions in space. It is there whether or not anything is present to feel it, and a probe placed at a point converts it back into a force.
AP Physics 2 names the idea directly for magnetism in EK 12.1.A.1, calling a magnetic field a vector field that can be used to determine the magnetic force exerted on moving electric charges, electric currents, or magnetic materials. EK 12.1.A.2 and EK 10.3.A.3 both add that the field is a vector quantity and can be represented using vector field maps.
A map is not the same drawing as field lines. A vector field map puts a separate arrow at each sample point, its length showing the strength there. Field lines are continuous curves whose spacing shows the strength. Lines never cross, since one point cannot hold two directions, and EK 12.1.A.2.i notes that magnetic field lines form closed loops.
Vectors add, numbers add separately. The net field at a point is the vector sum of the contributing fields, resolved into components. Electric potential attaches one signed number to each point instead, which is why potentials add as ordinary arithmetic with no angles involved.
The three in the AP courses: gravitational field in newtons per kilogram, electric field in newtons per coulomb, and magnetic field in teslas.