Your online host will have a "baked in" default scoring system. But, most leagues will modify these to fit their personal preferences, or most likely combine various scoring systems. The following are illustrations of different types of scoring systems:
Standard: A basic scoring system. The following points are awarded as follows:
Passing TD - 4 Points (some leagues prefer 6)
Run/catch/return TD - 6 Points
10 Yards Run or Reception - 1 point
20 Yards Passing - 1 point
Return TD (takeaway or kick) - 6 Points
Sacks/takeaways 1/2 points
Point Per Reception (PPR): This is the same as the Standard Scoring System, with the exception of the award of 1 point per reception. Some leagues will play 1/2 point per reception.
Touchdown Only: Points are only awarded for touchdowns (6 points for run/rec/ret), or 4 or 6 points for TD passes. Extra points, field goals, and two point conversions can also be awarded to your Defense/Special Teams position as described below.
Distance: This scoring system uses the Standard Scoring System with the option of adding some/all of the following scoring bonuses:
1 point bonus for each additional 10 yards. That is, a 10 yard td run or pass would get an additional point. A 20 yard td run or catch would get 2 additional points, and so forth.
1 point for every 10 yards run, or 20 yards in receiving
1 additional point for every 20 yards passing
Special bonuses for 100, 150 and 200 yards for running/receiving (5, 7, 10, e.g.)
Special bonuses for 300, 350, and 400+ yards passing (5, 7, 10, e.g.)
Field Goals - 3 pts for 1-39 yards, 4 pts for 40-49 yards, 5 pts for 50+ yards
Defense /Special Teams - 25 yards per point, 3 points @ 50 yards, 5 points @ 100 yards, e.g.
Additional Miscellaneous Scoring values that can be added to any league depending on your Host's settings capabilities. Some of these might be:
Offense
Interception (-1)
Sack (-1)
Fumble (-1)
Fumble lost (-2)
Offensive fumble return TD (6)
Pick six thrown (-3)
Fractional points (25 yards running would be scored 2.5, e.g.)
Defense
Sack (1)
Interception (2)
Fumble recovery (2)
Touchdown (6)
Safety (2)
Blocked kick (2)
Kickoff and Punt Return Touchdown (6)
Extra point returned (2)
Points allowed (the fewer points allowed, the more points earned):
0 points - (10)
1-6 points - (7)
7-13 points - (4)
14-20 points - (1)
21-27 points - (0)
28-34 points - (-1)
35+ points - (-4)
Individual Defensive Players (IDP): Some leagues will have a spot on their rosters in addition to a team defense, adding a defensive player. These players may be a defensive lineman, linebacker or a defensive back. Points may be scored as follows:
Sacks (4)
Takeaways (4)
Touchdowns (6)
Tackles (1.5 solo, .75 assist)
Lineman may also receive an extra point for a sack, and more for tackles (2 solo, 1 assist) to even out their scoring with the linebackers and defensive backs.
As you can see, there are a myriad of ways to score in fantasy football. That is the beauty of using an online host, because they do all of the scoring for you. The Commissioner of your league should be able to go into the Commissioner tools of your online host and adjust the scoring options to the preferences of your league. See the Commissioner Tools section of the website to see the settings we use.