Every race is different in Ignite. Each race brings something new as players try to win by using their own tactics. The score system in Ignite allows for tactics to be used during a race. Gathering score allows the use of nitro in the race and converts to time bonus at the end.
Most popular community and official game content for the past week.  (?)
What does popular mean?
It means the content you're seeing has been rated up more than it has been rated down for the given time period.