Development Kits, also known as development boards, are chip boards with a microprocessor. These kits provide a system to learn how to use a microprocessor. Additionally, they are programmable and have many uses. These kits can be used to create sounds, games, fiber optic communication, power supplies, relays, security devices, meters, motor controlers, robots and test computers. Many development kits have GPS, Bluetooth, Wi-Fi and USB. Many kits come with their own software for programming them. Development kits come with a ROM based built-in machine language monitor, or "debugger". In order to connect to a computer to program a development kit, the kits have ports to connect to the computer with.
Most development boards' software supports Mac OS, Windows and linux. Often programing languages for these kits are either c/c++, java, or their own language that resembles c/c++ or java. With these programming languages, you can tell the board to send power to a component. Most boards have their own IDE (Intergrated Development Enviroment), this helps with the programming through syntax correction and suggesting functions.
You can attach capacitors, resistors, switches, LEDs, relays, fuses, potentiometers, thermistors and varistors. With these, you can program the kit to react with these components. For example, you can have a thermistor, and when its exposed to a certain temperature, you can have an LED light up by programming the board to send power to the LED when that temperature is reached.
Many more complex things can be made with these kits as well. Depending on the board, one can create anything from a digital thermometer to sending text to an LCD screen to creating robots. When you add an accesory to the kit, you can do even more. Some accessories add new forms of communication, some add more memory for programming and some are adapters for a board's port to change for a computer.