Airlines. Traditionally, an airliner is divided into, from the fore to aft, first, business, and economy classes, sometimes referred to as cabins. In recent years, some airlines have added a premium economy class as an intermediate class between economy and business classes.
Passengers that fly First class can expect a superior experience with plenty of legroom, reclining seats, meal choices, full bar service or bartender, in-flight entertainment and Wi-Fi. It is a very comfortable and luxurious experience for each passenger who gets personal attention from flight staff.
In general, first class is the highest class offered, although some airlines have either branded their new products as above first class or offered business class as the highest class.
But this was a very solid economy class experience. It's hard to beat a one-way journey from Switzerland to the West Coast of the USA with a stopover in Amsterdam for 22K miles and about $120 in taxes. For that reason, I would not hesitate to use KLM again when traveling with the kids and using miles.