Indoor volleyball and indoor volleyball are variations of the same sport, but they have several key differences. The obvious difference is the playing surface (hence the name) and the number of players.

Comparing Volleyball Comparing Volleyball

 

Element Indoor Volleyball Beach Volleyball
Number of Players 6 players per team 2 players per team
Court Size 18m x 9m 16m x 8m
Playing Surface Hardwood or synthetic indoor court Sand
Ball Size Smaller and harder than a beach volleyball ball. It has a circumference of 65-67cm (25.5-26.5"), a weight of 260–280g Larger and softer to account for outdoor play. It has a circumference of 66-68cm (26-27"), a weight of 260–280g
Ball Material Usually made of leather made of water resistant material
Scoring System Best of 5 sets (first to 25 points, final set to 15) Best of 3 sets (first to 21 points, final set to 15)
Player Specialization Specialized positions (e.g., setter, libero) No specialization; both players must perform all roles
Net Height (Men) 2.43m (7'11") 2.43m (7'11")
Net Height (Women) 2.24m (7' 4") 2.24m (7' 4")
Substitutions Unlimited substitutions No substitutions allowed
Environment Indoor, climate-controlled Outdoor, weather can be a factor
Attire Athletic jerseys, shorts, knee pads Tank tops, shorts or bikinis
Serving Jump serves and spin serves common Float serves more common due to sand surface
Touch Limit 3 touches per side 3 touches per side
Blocking If the ball contacts the block it is not counted as a hit and the team still has three hits to return the ball. A block counts as a touch
Defense Strategy Teams can have a libero (a defensive specialist who is not allowed to serve or rotate to the front line) No libero; both players must defend equally.
Weather Impact No weather impact (controlled environment) Wind, sun, and other elements can affect play
Physical Conditioning Endurance and explosive movement Endurance with more emphasis on agility in the sand
Coaching Coaches are allowed during game and can give instructions. No coaching allowed during the game
Popularity Popular worldwide, especially in schools and colleges More popular in coastal and outdoor sports settings