This is the documentation of JSU for Jira Cloud. If you are using JSU on Jira Server or on Jira Data Center, you can find the documentation here.
Initially these features were provided by JSU but now on Jira Cloud they are maintained by Atlassian. The following workflow conditions are available:
For information on workflow conditions in Jira, see the Jira Documentation.
Our JSU on Jira Server/Data Center documentation about Workflow Conditions will also give you some hints, how to configure them on Jira Cloud.