Concurrency vs. Parallelism: How the OS Schedules Threads

Here we cover concurrency and parallelism. Along the way, we’ll explore processes and threads, the scheduler, ready and waiting work, physical cores and logical processors, and why creating more threads doesn’t guarantee more parallelism. We’ll also see why reducing the number of processes doesn’t necessarily reduce CPU load, and how developers can influence scheduling without controlling every decision. Programs organize work. The operating system schedules it. Hardware sets the capacity.