The phrase "economy cabin" refers to the section of an airplane where passengers who have purchased budget-friendly tickets typically sit. It is usually located towards the back of the plane and offers basic amenities compared to premium cabins.
This discount is valid for travel only in economy and premium economy cabins for roundtrip flights departing and returning to the same destination. (travelcodex.com)
Economy cabin seat pitch is an acceptable 31 - 32 inches; premium economy is 46 inches. (travelskills.com)
And therein lies an opportunity: You can find some great deals for very good seats in business class, premium economy and economy cabins when picking a flight served by the new planes! (dreamtravelonpoints.com)