Difference between using Redis plugin and installing it on the server

Thanks for quick reply. I’m not familiar with Redis but just heard it is good cache solution for the server. I actually meant What is the difference between using this plugin or following the tutorial below.

https://www.digitalocean.com/community/tutorials/how-to-set-up-redis-as-a-cache-for-mysql-with-php-on-ubuntu-20-04

What happens if I just simply install this plugin without doing anything else with regard to server?

I set it up and put a password for Redis. That’s it. I don’t know if I should do a configuration for Redis regarding caching, etc.