An inverter and a converter are different things.
A converter takes 120V power from the shore power or generator and turns it into 12V power to charge the house battery and power the 12V systems when the generator is running or you're connected to shore power.
An inverter takes 12V power and makes it into 120V power so you can run 120V stuff, at least to a limited extent, when you don't have the generator running or shore power available. Thus, it's the exact opposite or complement of a converter. (Some better/fancier/more expensive inverters are combination inverter/charger units, and these can take the place of a converter.)
The electrical center could very well house the converter; that's one common arrangement. In such cases, the converter itself is typically the lower section of the electrical center, with the circuit breakers and fuses above it. Alternately, the converter may also be a separate standalone box that's mounted just about anywhere in the RV.