They are generally programmed by the measurement while drilling (MWD) engineer or directional driller who transmits commands using surface equipment (typically using either pressure fluctuations in the mud column or variations in the drill string rotation) which the tool responds to, and gradually steers into the desired direction.
In other words, a tool designed to drill directionally with continuous rotation from the surface, eliminating the need to "slide" a mud motor.
Point-the-bit technologies cause the direction of the bit to change relative to the rest of the tool by bending the main shaft running through it.
This last benefit concerns geoscientists, because better measurements of the properties of the formation can be obtained, and the drillers, because the well casing or production string can be more easily run to the bottom of the hole.
Due to the relative high cost of this technology limited inroads to the lower end of the directional drilling marketplace have been achieved.