I have just started working on Mikrotik devices and I'm amazed with the amount of configurations you can do on it.
Right now we're working on a project that requires end users acquire prepaid login details from us before they can access the network. From what I understood hotspot, radius, and userman are all the same but different ways of achieving this. I appreciate any input you guys have, I can't wrap my head on how each differ from one another.

Both gives the same result. Controlling user rights.

Radius is a user manager, but for more complex setup. It uses a protocol to communicate with a server DB. Server gives control of Authentication Authorization, and Accounting.
User manager is just a local database of user that can be given access to your system.

Read more here:
https://en.wikipedia.org/wiki/RADIUS

It sounds like you would want to use Hotspot to create a captive portal when the user logs in to the network (hotspot intercepts traffic until the user logs in).
Then when they type their username/password in to the box Mikrotik will send a radius request (radius is a protocol) to userman to authenticate them. (userman is a radius server)

If you have a look here: https://blog.ibill.io/what-is-a-radius-server/ there's an overview of a PPPOE session dialling up using a radius server. It works the same on hotspot too.

Using the method "rossiza" describe, you will block the user (cable or wifi) until correct user/pass is entered.
Insted of giving out SSID and password, you can then have unique user/pass for each user.

It sounds like you would want to use Hotspot to create a captive portal when the user logs in to the network (hotspot intercepts traffic until the user logs in).
Then when they type their username/password in to the box Mikrotik will send a radius request (radius is a protocol) to userman to authenticate them. (userman is a radius server)

If you have a look here: https://blog.ibill.io/what-is-a-radius-server/ there's an overview of a PPPOE session dialling up using a radius server. It works the same on hotspot too.

Thanks for the explanation. Let me see if I understood it correctly, Mikrotik's own radius server is called userman, and if I wanted to use a remote(different) radius server I will configure it in the Radius tab just under the Log tab, it that right?

Thanks for the explanation. Let me see if I understood it correctly, Mikrotik's own radius server is called userman, and if I wanted to use a remote(different) radius server I will configure it in the Radius tab just under the Log tab, it that right?

You would still need to configure the radius tab in Mikrotik (the one generating radius requests - the hotspot). Userman may or not may not live on the local ip address of the Mikrotik (it could be a remote mikrotik). You would also need to enable radius in your hotspot profile.

On the userman side, the router will need to be added, even if it's the same router (/tool user-manager router). Each "radius client" (router) needs it's IP specified along with a shared secret, otherwise the packets will not be accepted by the radius server. The shared secret specified in user-manager routers should match the shared secret specified on the hotspot (radius client).