When you see a profile on home feed you have the options swipe or like them. If you swipe someone it means you do not interested in him/her. If you like someone a notification is sent to him/her and if they like you back it will be a match. When you refresh the home feed all the previous profiles you’ve swiped or liked considered as seen and not displayed in your feed anymore. So you always see new people to discover and like on your feed.