Explain the Reading documentation for a class in the class library

For instance, let's suppose you need to use the URL class in the java.net package. Through reading the documentation for the class you discover that it has the subsequent public methods and constructors:

public URL(String protocol, String host, int port, String file)
throws MalformedURLException
public URL(String protocol, String host, String file)
throws MalformedURLException
public URL(String spec) throws MalformedURLException
public URL(URL context, String spec) throws MalformedURLException
public int getPort()
public String getFile()
public String getProtocol()
public String getHost()
public String getRef()
public boolean equals(Object obj)
public int hashCode()
public boolean sameFile(URL other)
public String toString()
public URLConnection openConnection() throws IOException
public final InputStream openStream() throws IOException
public static synchronized void
setURLStreamHandlerFactory(URLStreamHandlerFactory factory)

You use this class only like you'd use any other class with these techniques which happens to be named java.net.URL.