The iRacing Progression is the standard series progression through the iRacing License Levels. The iRacing License Levels are Rookie, D, C, B, A, Pro, and Pro/WC. Note: Once you are out of the rookie license in any license progression area, you can never go back to the rookie license.
Also, you can progress your iRacing license via Time Trials (against the clock) or in Races. Other modes include Qualify (for starting grid position), Practice (preparing for the race with other drivers), Test (learning the track by yourself), and Time Attack (similar to Time Trials but doesn't affect safety rating).
Please Note that Time Trials can only bring your iRacing License up to the A Class. If you are after the Pro Licenses (Pro and Pro/WC), you will have to participate in races.
Types of Racing Include: NASCAR, Indycar, Indy Lights, F1, IMSA, Formula 2, Prototypes, V8 Supercars, Dirt Oval, Formula 3, TCR, GT4, Rallycross, and Lucas Oil Offroad.
Top Class: Yellow
2nd Class: Blue
3rd Class: Pink
4th Class: Purple
5th Class: Green
6th Class: Orange
7th Class: White