Is concurrent and parallel execution of program parts the same?

Concurrent and parallel execution are related but different concepts.

• Concurrency is the ability of a system to manage multiple tasks that can be executed simultaneously or alternately, switching between them. In Go, this is implemented through goroutines, which can be started and paused by the scheduler.

• Parallelism is the simultaneous execution of multiple tasks on different CPU cores.

In other words, concurrency is about the structure of the program and task management, while parallelism is about the physical simultaneous execution.

In Go, goroutines provide concurrency, and if you have multiple CPU cores and GOMAXPROCS > 1 enabled, goroutines can run in parallel.