What is meant by tidal locking?

"Tidal locking refers to when an object in orbit around another object always has the same face pointing towards the planet - the time taken for one rotation of the body would therefore be the same time that it takes to orbit once around the object that it is tidally locked to. This does not occur by chance, the irregular mass distribution of an orbiting body will cause it to become tidally locked over time, but further back in time it may have spun at a different rate. One example of a tidally locked object is our moon. It is tidally locked to the earth, meaning that the same face always faces the earth. It is thought that this may have not always been the case but has happened over time. Other moons in our solar system are also locked to their planets. In some cases, both object may eventually become tidally locked to each other, two objects in orbit about one another may reach a state where they both always have the same face directed at each other."

Perfect, thank you megan