Can all different makes of two-way radio’s communicate? For example Motorolla;Cobra; and Midland?
It’s not so much the brand as the service (set of frequencies) that the radios use that makes them compatible. For example, a Motorola business radio is not compatible with a Motorola GMRS consumer radio. However, a Motorola GMRS radio is fully compatible with a Midland or a Cobra GMRS radio.
Based on the brands that you mentioned, most likely you are looking at consumer radios that use the FRS and GMRS services and, yes, they are all compatible.