Whats the difference between Methods and Members in C++? -

this beginner question. i'm pretty sure many people had doubt still didn't find clearfy mind, maybe i'm looking in wrong direction or conception. thing is, can work both codes:

    sf::clock clock;     clock.getelapsedtime();      sf::clock getelapsedtime(); 

both accepted through ide can't understand difference. programm other languages know clock.getelapsedtime(); return time during app open, sf::clock getelapsedtime(); exactly?

thanks in advance

first calls member function getelapsedtime through object named clock while,
second declares non-member (free) function name getelapsedtime returns object of type sf::clock , takes no arguments.

good read:
what function declaration?