Cuckoo Clocks work through the use of a pendulum, which is normally fully exposed and are considered to be a type of cast iron weights. These are often shaped like pine cones, which a type of rustic country style to the clock itself. Cuckoo Clocks can have the choice of an eight day movement or a one day movement, but all traditional Cuckoo Clocks will produce the cuckoo sound by passing puffs of air through two tiny little pipes within the clock itself.

There are some Cuckoo Clocks that have a type of musical movement that will play a song after the hour sound, which may be a traditional German song or often it is Edelweiss. Today there are quartz Cuckoo Clocks being made, which are battery powered instead of using pendulums and weights to keep time. Of course, these are not as authentic as the more traditional mechanical Cuckoo Clocks and they are not as near as popular with collectors either, especially since they use animated plastic cuckoos and even have a recorded cuckoo sound.

The second most popular clock that collectors enjoy collecting is the Grandfather Clock, which like the Cuckoo Clocks are weight driven by pendulum, but their pendulums are encased. A tall case is required for due to the pendulum and the weights of these clocks being so extremely long, and are displayed behind a glass frame. The casing of the Grandfather Clock most often features and special design that will surround the frame of the face of the clock. The majority of Grandfather Clocks operates on a striking mechanism like a gong, a bell, or a chime, which will sound at top of each hour.

The Grandfather Clock has either an eight day movement or a thirty hour movement, but with an eight day movement the clock will require being wound only once a week while a thirty hour movement requires being wound every single day. Of course, this can be a big inconvenience and that is why most of the Grandfather Clocks being produced today use an eight day movement. However, collectors are finding that there are more older thirty hour movement Grandfather Clocks in exist because of their longevity than older eight day movement Grandfather Clocks.

Collectors have found that there are a variety of different sizes and styles of Grandfather Clocks available, which range from six to eight feet tall and are no more than three feet wide. However, there are more compact and slightly shorter Grandfather Clocks that are five to six feet tall and the styling is more traditional. The cases of Grandfather Clocks can be made of different types of wood and a variety of finishes also, and will even fit with any decor that a collector may have.

Some collectors will collect the more traditional type Grandfather Clocks that are decorated with ornamental carvings and have an old fashioned grace. While other collectors collect the contemporary type Grandfather Clock that are decorated will simple distinction in any room.