Goroutines and channels versus thread-based concurrency
A goroutine is a function that runs concurrently with other goroutines, scheduled by the Go runtime rather than the operating system, which makes them far cheaper to create than OS threads: a Go program can run tens of thousands of goroutines where a thread-per-request model would exhaust system resources. Channels give goroutines a way to communicate and synchronize without the shared-memory locking patterns that make concurrent code hard to reason about in many other languages.
The practical effect on projects we build is that concurrent code stays readable: a worker pool processing a queue, or a service fanning a request out to several downstream calls and collecting the results, reads as straightforward sequential code with channels marking the handoff points, rather than callback chains or heavy async syntax threaded through every function signature.









