What are the different classes on Japanese trains? Which ones are included in the Japan Rail Pass?

There are two different classes on Japanese trains: Ordinary class and Green class. Among these classes both are included in the Japan Rain Pass, but it depends on which pass is purchased.

Purchasing the Ordinary Japan Rail Pass allows you to enjoy unlimited rides on the Japan Rail network including bullet trains (Shinkansen) across Japan. However the Ordinary JR Pass only gives you access to the ordinary class cars.

Purchasing the Green (First class) Japan Rail Pass provides you with all the Ordinary Japan Rail Pass benefits, plus access to the first class cars, which are more spacious and quiet. There are no non-reserved seats in Green Class, so seat reservation (free) is compulsory before boarding a green car.

On certain JR Shinkansen lines there is one more class available: Gran Class. This luxury class offers plush leather seats and high-end food and drinks as you travel. Gran Class is NOT included with any JR Pass, however it is possible to upgrade for a significant additional fee.