Monimoto EU (MM1/MM5) supports European GSM bands and works on 2G network only. Monimoto Global (MM2/MM6) has 2G/3G capabilities and can work with any global carrier. There are more 3G cellular towers available throughout the world than 2G, therefore Monimoto Global (MM2/MM6) has better coverage and better location precision indoors and in the cases of no GPS signal.
In other words, Monimoto Global (MM2/MM6) works in most countries of the world while Monimoto EU version (MM1/MM5) works in European Union plus several other countries. See list of MM1/MM5 supported countries here and more details on MM2/MM6 here.