Internal clocks are a type of clocks that are built into a computer or other electronic device. They are used to measure and control time, such as in controlling computers, synchronizing networks, or creating timestamps. Internal clocks are usually very accurate and can achieve an accuracy of a few milliseconds. They can also be used as a substitute for an external clock when no external clock is available. Internal clocks are usually very inexpensive and can be found in many different shapes and sizes. They are also very easy to install and use.