this is the concept of process / thread / concurrency / cpu scheduling that I extracted from the network:

• process is a computing activity of programs that can be executed concurrently on a certain data set, and it is also the basic unit of resource allocation and scheduling for the operating system.
• Thread is an entity that can execute concurrently in the process of the operating system, and is the basic unit of processor scheduling and dispatch.
• concurrency , multiple tasks on the same CPU core take turns (alternately) according to subdivided time slices, and logically those tasks are executed at the same time. For the CPU kernel, tasks are still executed in a fine-grained serial fashion.
• simultaneous execution is not really simultaneous execution, because only one process can execute at any one time in a single cpu kernel.

then, I have some questions:

1. cpu is actually concerned with threads, and processes are just a collection of threads, that is, abstract concepts, which do not actually exist.
The so-called concurrency in
2. actually describes thread concurrency. Because cpu only knows threads, it is also threads that are scheduled in the end.

?