Mbed OS reference book
This section gives background reference information about Mbed OS. This content includes architectural details and technical information about the configuration system.
Arm Mbed OS lets you write applications that run on embedded devices, by providing the layer that interprets your application's code in a way the hardware can understand.
Your application code is written in C++. Your code uses the application programming interfaces (APIs) that Mbed OS provides. These APIs allow your code to work on different microcontrollers in a uniform way. This reduces a lot of the challenges in getting started with microcontrollers.
This is the basic architecture of an Mbed board: