What is a context in Go?

In Go, context is a package and a concept used to pass information about request lifetime, cancel operations, and transfer values between goroutines.

Main tasks of context:

• Managing cancellation of operations (e.g., on timeout or user request cancellation).
• Passing deadlines (the time by which an operation should complete).
• Passing request-related values (e.g., identifiers, tokens).

Example of usage:

ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
// Cancel after 5 seconds timeout

go func(ctx context.Context) {
    select {
    case <-time.After(time.Second * 10):
        fmt.Println("operation completed")
    case <-ctx.Done():
        fmt.Println("operation cancelled or timed out")
    }
}(ctx)

// Call cancel at the end to free resources
cancel()

Thus, context helps control the lifecycle of operations and coordinate work between goroutines.