¿Is there documentation to know what means every variable and what acepts?

Summary:

I want to know if there is docuentation to know what means variable availables and what acepts.

Content (please ensure you mask any confidential information):

Here an example, there are variable but in some moment I don't know what they means or acepts, with documentatio about that it would be easier for me also to use advance mode for edit the condition. I know that there is an icon in the left of varible and that is one way, buy I want to know more information about that, how acces to some value and some stuff like that. Thanks in advance.