What is a goroutine in Go?

A goroutine is a mechanism for concurrency in Go. It is a lightweight thread managed by the Go runtime. Goroutines can be easily created in Go programs and used to execute functions or methods in parallel. In Go, starting a goroutine is very simple; you just prefix the function call with the go keyword. This causes the function to execute concurrently in a new goroutine. This mechanism is highly efficient because the Go runtime automatically schedules these goroutines on available physical threads and handles their lifecycle and memory usage, allowing developers to avoid the complexities of synchronization issues and thread management that are typical with traditional threads.