How do goroutines differ from OS threads?

Goroutines in Go are lightweight threads managed by the Go runtime, not the operating system. Key differences:

• Lightweight: Goroutines use much less memory (usually a few kilobytes of stack), whereas OS threads require significantly more resources.
• Scheduling: The Go runtime's scheduler manages goroutines at the user level, allowing efficient switching between goroutines without kernel intervention.
• Scalability: Thousands or even millions of goroutines can run simultaneously, which is practically impossible with OS threads.
• Communication: Goroutines typically communicate via channels, simplifying synchronization and data exchange.

Example of creating a goroutine:

package main
import (
    "fmt"
    "time"
)

func sayHello() {
    fmt.Println("Hello from goroutine")
}

func main() {
    go sayHello() // start goroutine
    time.Sleep(time.Second) // give the goroutine time to execute
}

Thus, goroutines are an efficient way to perform parallel code execution with low overhead.