In short
- On your PC it is free, but the bot is only connected while your computer is.
- Free services often have limits on memory, uptime or support.
- Paying is worth it when others depend on your bot or you do not want to look after a machine that stays on.
On your own computer
It is free, but the bot is only connected while your PC is on and online. It works for testing, not for a bot that others use daily.
On a free service
Some free services let you host a bot without paying. They often have limits on memory, uptime or support, so read their conditions before relying on them.
On a paid host
You pay for a space built for bots, with the language already installed, assigned memory, FTP upload, a panel to start and restart it and logs to see errors.
What to look for
That it supports your bot's language, how much memory each plan includes, how you upload files, whether you can see the logs and whether you can restart it yourself from a panel.
When paying is worth it
When other people depend on your bot, when you want it always connected or when you do not want to look after a machine that has to stay on.