Walkie-Talkie Repeater vs. Non-Repeater

Walkie-Talkie Repeater vs. Non-Repeater, that's the question. Now, before I research repeater, and finding out what is a repeater and what it does, I had no idea. But, at the same time, I should've knew what a REPEATER was, what it is, is the title.
Now, a repeaters has to do with Walkie-Talkies...of course, but you don't really need it, if you don't want everyone who is on your channel, to wear some people.
Here's what I am talking about.
Say if you have 5 Handheld Radio and one of them is the "Base", which is where the single comes from, and you have an 20-Mile Radius, everyone will hear you, but they might not hear each other.
Now, a repeaters has to do with Walkie-Talkies...of course, but you don't really need it, if you don't want everyone who is on your channel, to wear some people.
Here's what I am talking about.
Say if you have 5 Handheld Radio and one of them is the "Base", which is where the single comes from, and you have an 20-Mile Radius, everyone will hear you, but they might not hear each other.
Now, the circle above, is your "20-Mile Radius", and you "the handheld "Base"", is in the middle. When you "Key Up" to talk, both Person A and B will hear you, and you can hear both Person A and B. But, Person A can not hear Person B, and Person B can not hear Person A.
Now, in this circle above, is with a repeater. The repeater is in the middle, and when Person A "Key Up" and talk, now with the repeater, anyone who is in this "circle", can hear and talk to everyone else.