This course contain basics fundamental knowledge of real time operating systems, Real-time operating systems focus on applications that are running and typically give little importance to applications in waiting. That means fewer tasks or applications are managed, so the system can give more exact results on present execution work. A real-time scheduling System is composed of the scheduler, clock and the processing hardware elements. In a real-time system, a process or task has schedulability; tasks are accepted by a real-time system and completed as specified by the task deadline depending on the characteristic of the scheduling algorithm. In this course learner will study basic components of real time operating system, Need of RTOS. Different features to select the RTOS. Also this course focus on different types of real time task, like periodic, aperiodic, sporadic task. This course include temporal parameter like Execution time , Absolute deadline, Relative deadline. It is focus on functional and resource parameter of real time process, like Permittivity of job, Criticality, optional execution , Laxity type and laxity function and resource parameter like resource graph , preemptive resources. This course consist of different approaches to real time scheduling like clock driven, weighted round robin, priority driven approach. also explained priority driven scheduling algorithm with the help of example.Earliest deadline first , Rate monotonic scheduling, Least slack time, Latest release time scheduling algorithms are explained with the help of examples in very well manner.