Wouldn't that make each round just 1 second long? Seems like a short amount of time to perform actions and move.
The confusion, I think, stems from the fact that the terms "round" and "turn" had different meanings in all previous versions of D&D, which is why I frequently see people get it wrong.
It's also why some DMs try to limit how many times a rogue can sneak attack in a round.
From the basic rules page 69
The Order of Combat
A typical combat encounter is a clash between two sides,
a flurry of weapon swings, feints, parries, footwork, and
spellcasting. The game organizes the chaos of combat
into a cycle of
rounds and
turns. A
round represents
about 6 seconds in the game world. During a round, each
participant in a battle takes a turn. The order of turns is
determined at the beginning of a combat encounter, when
everyone rolls initiative. Once everyone has taken a turn,
the fight continues to the next round if neither side has
defeated the other.
Here they are referring to combat rounds (other places refer to a round for and individual, such as duration).
But yes, it's assumed that a round lasts about 6 seconds. There can be as many, or as few turns as there are combatants.
Remember that D&D is a gross over-simplification of virtually simultaneous activity in combat, and is one of those things like Hit Points or Armor class that it simply isn't worth thinking too much about.
