Radius server.

Hello to all.
I am new to microtik technology.
I have a rb450g in my hands and I see that supports radius server authentication.
My question is pretty simple.
Do I have to use a seperate radius server pc in order to accomplish the authentication that I want for my users?
Or there is an inbuild way to do it threw the routerboard and the os on it?

If the second is true witch os supports these functions and is there any tutorial for this?

Thank you in advance for your time!

https://vimeo.com/51232471

dear watch this it may help you

Thank you!
Was really really helpfull!!!