The main difference between a geyser and a hot spring is that a geyser is plugged with an obstruction near the opening of the spout and a hot spring is allowed to flow freely. Both geysers and hot springs get their water from rain and snow that melts and seeps into the ground, which is then heated by magma.
A hot spring is also different in that it gives off steam when the water comes near the surface. Constrictions in plumbing network of a geyser keeps the water boiling underground, which helps create the pressure that causes the water to rise out of the ground spontaneously.
