Basics of O.S

Basics of O.S

An operating system is a control program. A control program manages the execution of user programs to prevent errors and improper use of the computer. It is especially concerned with the operation and control of I/O devices.

An operating system as a resource allocator. A computer system has many resources that may be required to solve a problem:

Mobile operating systems often include not only a core kernel but also middleware : a set of software frameworks that provide additional services to application developers. 

Middleware 

A typical operating system provides an application programming interface (API) for programs to utilize underlying hardware features. Middleware, however, provides an API for utilizing underlying operating system features.

Middleware is a software layer placed between applications and operating systems.

Bootstrap (Basic of O.S)

When it is powered up or rebooted—it needs to have an initial program to run. This initial program, or bootstrap program, tends to be simple. Typically, it is stored within the computer hardware in read-only memory (ROM)

The bootstrap program must know how to load the operating system and how to start executing that system. To accomplish this goal, the bootstrap program must locate the operating-system kernel and load it into memory.

Once the kernel is loaded and executing, it can start providing services to the system and its users.