A DIMM, or Dual In-line Memory Module, is a type of computer memory module used to store data temporarily while a computer is running. DIMMs are commonly found in desktop computers and servers, providing the necessary memory for the system to operate efficiently. They have a 64-bit data width, which allows for faster data transfer compared to older memory types. DIMMs come in various sizes and speeds, with different types such as DDR, DDR2, DDR3, and DDR4, each offering improvements in performance and energy efficiency. The physical design of DIMMs includes a series of memory chips mounted on a circuit board, making them easy to install and replace in compatible motherboards.