Indoor and Arena Football have a lot of similarities but they also have a lot of differences. Both styles of play use Hockey Rinks (well, most teams try too find hockey rinks) and play on an astroturf feild of 50 yards in length and both play 8 man football instead of the standard 11 man American Football.
As much as poeople don't realize, Indoor Football and Arena Football have a lot of diffences. The most noticable diffence is that Arena Football uses rebound nets while Indoor Football does not. The main reason for this is that the AFL has that special patent that keeps any body else from using the same or similar system. Indoor Football does not have any Rebound nets at the back of each endzone, all Indoor Leagues have is a Standard Goal post for Feild Goal attempts. The Rebound nets in Arena Football ard designed too keep Kicked balls within the feild of play on Kickoffs and Feildgoal attempts, while Indoor Fotoball uses specail rules too force teams too keep the ball in the play of the game. Other major rule differences is that Arean Football use "Ironman" rules (which means most players MUST play both ways) while most Indoor Leagues do not have any mandatory Ironman rules. Indoor Football uses a Platoon system like Outdoor Football does (an Offense and a Defense). Both Arena Football and Indoor Football uses special Defensive rules aswell. In Arena Football, they use what is called a "Box" rule where their must be 5 Defenders and must be 5 Offensive players inside an imaginary box that as wide as the tackles on offense and is 5 yards deep and 5 yards behind the LOS. Arena Football has this rule in order too create a lot more passing then rushing in their game. In Indoor Football, most leagues use what is called an "Alley Rule" which is suppose too be an imaginary Box that starts at the Line of Scrimage on Defense and is 5 yards deep and is the width of the Offensive tackles on Offense. Only the 3 Down Defensive Linemen may be inside this box, all Linebackers or Defensive backs must stay out of the Alley until the Ball is snapped. The idea of the Alley rule is too allow more rushing in the Indoor game and is a little tougher too blitz the QB. Basically, the Alley Rule does the exact opposite of what the Box rule does.
These are the main differences between the two styles of games. The main reason why I like Indoor Football more then Arena is that its feels more like the Outdoor game and their is more defense then Arena Football. Arena Football does not like Indoor Football because they feel its copying "their" game yet they can do little too stop Indoor Football leagues from starting because their Patent is limited too what it can enforce (basically, the rebound nets are the only thing that Arena Football can disput). Indoor Football is mostly played in small towns in the U.S. because small communities have more interet then the big markets and the style of game is more like Outdoor Football (with more rushing and more defense then Arena Football). Because of Indoor Footballs success in certain parts of the U.S., Arena Football created the AF2 (Arena Football League 2) in order too destroy Indoor Footballs chances of establishing itself in small markets, and too make the game of Arena Football more popular. Both Indoor Football and AF2 play during the Spring/summer months when Basketball and Hockey are in the offseason where Arena Dates are available, except the AFL which is playing during the months between Febuary and June.
These are the main differences between the two styles of games.