Inverter vs Multiplus and Outlets

[Vernation]

I'm a total noob and don't understand the talk about how with an inverter you can't have as many outlets working as you can with an inverter/charger.


There are only 5 outlets in my trailer as it is. Does this mean that some of them can't be wired to the inverter? If an outlet has two receptacles, is one for the inverter and the other for shore power? You have two separate circuits?
How does this work?


The Multiplus sounds cool, but I wonder if it is overkill for my application. Sounds like you need a certain amount of batteries connected to it and a certain amount of space for air circulation and it makes noise... Plus my lack of roof space means I probably won't be on the cutting edge one way or another.
I'm wondering if a standard inverter will do everything I need for less money.


Could you please explain these basic points of trailer electricity that, being new to this world, I didn't know was even a thing?