Congratulations!
Are you referring to the 'Cottage Economy' versus the 'Specialist Economy' (similar to the 'Farm Economy'?). If so a simple explanation might be;
A Cottage Economy is about placing as many workable Cottage improvements down as practicable in an empire's Commerce-oriented cities. These tiles are frequently worked in order to get them to grow into Towns. As noted earlier, you still need to have food in order for your city to grow in population so the Cottages can be worked in the first place. This type of approach particularly suits leaders with the Financial trait.
A Specialist Economy will put Farms on its Floodplains and Grasslands instead of Cottages so it can create a food surplus. This food will then feed Specialist citizens as Specialists consume two
each - the Specialists can be assigned whether it's through The Caste System civic or through buildings in the city (for example; Libraries allow Specialist Scientists). The idea is (in part) to generate Great People points and pop plenty of Great People. The Specialists themselves of course do more than generate Great People points, so you can run a fairly healthy economy with the contribution that specialists make to 
, 
, 
, or 
. This type of approach particularly suits leaders with the Philosophical trait.Cottage Economy = Lots of Cottages, some Farms, no particular effort to Specialists > Great People.
Specialist Economy = Lots of Farms, lots of Specialists > Great People.
This whole thing has been debated at some length, and there are lots of complicating arguments 'and what not' that I won't launch into here.
Many players opt for a mix of both, with one or two cities dedicated to
production (also referred to as Great Person Farms) while still having some Commercially-oriented cities with a high proportion of worked Cottages.
