Centrifugal force is actually a virtual force that arises only in the curved reference frame of orbits; it acts to pull orbiting objects outward.

An object traveling in a circle, even at constant speed, is accelerating. That's because its direction is constantly changing to point to the center of the circular path — a condition that's defined as centripetal acceleration, as expressed in the equation here. When this acts on mass objects, it generates centripetal force.

Centripetal force keeps objects from hurtling off on a straight path.

With the same Latin root as pedal, the suffix -petal translates to ftraveling — centripetal force is a “center heading” force. Electromagnetic forces, nuclear forces, and even gravity (in bodies orbiting in space and on Earth) can keep objects on circular paths by acting as centripetal-force sources.

Select figure to enlarge.

Comic copyright and courtesy of xkcd.com.

With the same Latin root as fugitive, the suffix -fugal translates to fleeing — centrifugal force is a “center fleeing” force. This is a pseudoforce, an equal but opposite reaction to centripetal force (according to Newton's Third Law) so practical calculations generally only derive centripetal force.