What Android are the best for your phone?

[RoseKaizer]

I have a lot of phone that I used since android phone was released. And different android version was also released, like nougat,marshmallow,kitkat,jellybean,gingerbread and more..But the best android version for me was the jellybean..
What is yours?

 

[Dracindo]

Wait, there's more than 1 Android? I've heard about different Android versions, just like there are different versions of Windows, like XP, 7, 8, 10, Vista and what not. But this is completely new to me.

Can someone explain me what the difference is between these Androids, and how I can switch to another version, should there be a version that I find more appealing? Or is this something that depends on the device your using? And how do I know what I'm using? I'm happy with what I'm using though, but again, I have no idea what benefits I have over the other types of Android.