In the Swift URL Documentation, there are several ways to add a String as part component into the URL. But which one should I use?

I know the difference between append() and appending(), the former is to create new URL while the later is to append it directly into this one. But what’s the difference between appending(path:), appending(component:), and appendingPathComponent()? I cannot find any difference? Which one should I use?

func appending<S>(path: S, directoryHint: URL.DirectoryHint) -> URL
func appending<S>(component: S, directoryHint: URL.DirectoryHint) -> URL
func appendingPathComponent(String) -> URL
func appendingPathComponent(String, isDirectory: Bool) -> URL