Differences in CRJs

What exactly is the difference between a CRJ-200 and a CRJ-440? Apparently the only difference I could find is one is 50 seats and the other is 44 but I flew on a CRJ-440 yesterday that was probably converted to 50 seats (N8698A).

And while I’m on this subject, how about between a CRJ-700, CRJ-701, and CRJ-705?

More info than I care to type:

en.wikipedia.org/wiki/Bombardier_CRJ700#CRJ705

It does appear the 440 was just a 100 or 200 with fewer seats, probably to meet the scope clauses of some airlines.

The CRJ100, CRJ200, and CRJ440 are all the same aircraft with the following differences:
440: only 44 passengers
200: a 100 with GE engines

The 200 is a marketing name. It is certified as a 100.

Airilners.net article
Type Certificate Data Sheet

Pictures

The -700 is limited to 68 pax, the -701 to 70 pax and the -702 to 78 pax. The -705 is based off the -900 but has only 75 seats to fit within some airline’s pilot contracts that prohibit any aircraft with more than 75 seats unless it is flown by mainline pilots.

And yes, all former NW Airlink CRJ-440’s fitted with 44 seats have been converted to seat 50.