Multiprogramming is a technique where multiple programs are loaded into memory and executed by the CPU. The primary goal is to maximize CPU utilization by ensuring that it remains busy as often as possible.
Increase CPU utilization.
The CPU switches between programs, allowing it to work on different tasks without being idle.
Only one program runs at a time, but the CPU switches among them.
Running a word processor and a spreadsheet application at the same time on an old system with limited memory.
Multitasking is the ability of an operating system to execute multiple tasks or processes seemingly simultaneously. It can be divided into two types preemptive multitasking and cooperative multitasking.
Allow multiple processes or tasks to share the CPU effectively.
The CPU is rapidly switched between tasks so that each task gets a share of the CPU time.
Multiple tasks or processes appear to run concurrently due to context switching.
Using a web browser while downloading files and listening to music on a modern OS.
Multithreading is a technique where a single process is divided into multiple threads, which can be executed concurrently. Each thread represents a separate path of execution within the same process.
Improve the efficiency and performance of a single process.
Threads within the same process share the same memory space, making communication between threads easier and more efficient.
Multiple threads run in parallel within a single process, sharing resources and data.
A web server handling multiple requests concurrently, where each request is handled by a different thread.
Multiprocessing refers to the use of two or more CPUs (or cores) within a single computer system to execute multiple processes simultaneously.
Increase overall computational power and performance by leveraging multiple CPUs or cores.
Multiple processes run truly in parallel on different CPUs or cores.
Each process runs independently, with its own memory space, on different processors.
A high-performance computing system running complex simulations across multiple processors.
Multiple programs in memory; CPU switches between them to keep it busy.
Multiple tasks or processes share the CPU by context switching; can be preemptive or cooperative.
Multiple threads within a single process run concurrently, sharing the same memory space.
Multiple CPUs or cores execute processes simultaneously, each with its own memory space.
Each of these techniques aims to improve system efficiency and performance in different ways.
