An Real-Time Operation System or RTOS is simple multitasking operating system. The advantages include faster response and more modulare code design.
There are two main implementations of a RTOS, cooperative and preemptive. A cooperative system uses a timer loop to switch between tasks when they are completed. This provides a good approximation of multitasking while being very light and easy to implement. A preemptive system usues interrupts to switch tasks. This is true nultitasking, but involves a lot of work and is more resourse intensive.
Below is the link to DuinOS and FreeRTOS, both things to look into in the future.