What are the pros and cons of outdoor and indoor soccer?
Outdoor soccer is more appealing as we are out in nature. 
The outdoor field is bigger
Outdoor soccer is most popular
Major soccer tournaments worldwide are played outdoors, including the World Cup

Indoor soccer is good to play when the weather outside is bad
Indoor soccer often results in way more touches on the ball for a player. 
Indoor soccer has some unique strategies that can make the sport more interesting. 
Indoor soccer tends to have more goals scored and hence more entertainment.