Important OS

Types of OS

1. Single Process
2. Batch Processing
3. Multiprogramming - multi jobs/ programs running
4. Multi-tasking - extension of 3 logically - single CPU able to run multiple task simultaneously.
5. Multiprocessing - more than 1 CPU single computer
6. Distributed - more CPUs, memory GPUs are or maybe in more than oen place it is distributed.
7. Real Time -

Multi-tasking vs Multi-Threading

Multi-Tasking

working with many tasks simultaneously.
CPU switches from multiple processes.
eg. employees working in same company(CPU) in different departments(Processes) in their offices(their memory).

Multi-Threading

Breaking a process into several threads which has there own path of execution.
CPU switches between threads from same process, sharing memory.
eg. employees working in same company(CPU) in same project(Processes) in same office(their memory).

Note: in multithreading each thread is executing based on priorities. Each thread their own time slices in the runtime(whole process has the same runtime).