The full name of the micro:bit is BBC micro:bit, which is a single-chip microcomputer. It is designed to help children (or adults) learn computers, coding, electronics and natural sciences. Many elementary and middle school courses also teach micro:bit as a STEM course.
It is very easy to write programs on the micro:bit, because it has a graphical interface (makecode) to write programs. You only need to drag and drop patterns to write programs to achieve the purpose you want.
The micro:bit has an LED display, buttons, sensors, and many I/O functions, and can be programmed to interact with the world, helping you learn how software and hardware work.
The micro:bit can also be connected to various sensors, such as infrared sensors, ultrasonic sensors, motor servers, etc., so it can do various interesting experiments, which is very suitable for teaching STEM knowledge.