Unlike with Constructed, in Limited players don't have to bring their own cards but instead receive unopened booster packs to build their decks. Limited generally means Sealed Deck for a tournament's Swiss rounds and Booster Draft for the Top 8 playoffs.
While success in Limited may depend on the cards opened, there's no advantage for players who own a large collection. It is popular with beginning players for that very reason and with seasoned veterans because every deck and every game is different. As every player enters the tournament with exactly equal chances to get a strong pool of cards, Limited is the ultimate test of one's skill!