Colour wheels
Also called: color wheels, lift gamma gain, shadows midtones highlights
Three wheels, labelled lift, gamma and gain in some software and shadows, midtones and highlights in others. Dragging the point inside a wheel pushes the colour of that tonal range towards the hue you drag towards, and the slider beneath it raises or lowers brightness for that range alone. A fourth offset or master control moves everything at once.
They belong to the primary pass: neutralise a colour cast, set the black and white points, then place the overall mood. Secondaries, curves and looks come afterwards. The usual mistakes are grading before exposure is right and grading on a screen nobody has ever calibrated, which produces footage that looks correct to you and green to everyone else.