In Go, goroutines are lightweight threads of execution that are managed by the Go runtime. Goroutines are multiplexed onto a smaller set of operating system threads, allowing many goroutines to run concurrently on a single machine. Goroutines are created using the **go** keyword, which starts a new goroutine that runs a given function in the background while the main program continues to execute.
Threads, on the other hand, are managed by the operating system and are typically heavier weight than goroutines. They require more system resources to create and manage, and switching between threads can be relatively expensive. Because of this, it is typically more difficult to create and manage large numbers of threads compared to goroutines.
In summary, while both goroutines and threads provide a mechanism for concurrent and parallel programming, goroutines are lighter weight and easier to create and manage in Go.