There are two types of volleyball, the normal kind played indoors and the more glamorous beach volleyball played outside.
Because of the (small) outfits the players wear they often attract headlines for how they look rather than how they play.
That's a shame, because beach volleyball can be a thrilling sport to watch as it is very fast moving.
Inside, each team has six players with another six on the sidelines.
The idea is to get the ball from your side of the court, over a high net, without it touching the ground.
It is allowed to be touched three times by a team, but must be hit over the net before a fourth touch or it hits the ground.
In beach volleyball, whichever team forces the ball to hit the ground on the other side of the net wins the point.
Now that this rule has been adopted indoors too, although in the past only the serving team was able to score points.
Who are the British hopes?
There aren't any British volleyball players in Athens.
Who are the big names?
Bizarrely, for a country with no coastline, Switzerland's men are really good at beach volleyball.
They have three of the world's top teams but there is only space for two of them in Athens.
In the women's event it is the Brazilian pairing of Sandra Connelly and Ana Donnelly who lead the world rankings, with Pires having won Olympic gold in 1996.