Collections

To make user's life easier, "collections" are available, which are just a bundle of parsers and scenarios. In this way, if you want to cover basic use-cases of let's say "nginx", you can just install the crowdsecurity/nginx collection that is composed of crowdsecurity/nginx-logs parser, as well as generic http scenarios such as crowdsecurity/base-http-scenarios.
You can find more about this in the CrowdSec documentation.