Session is a key/value data stored in scenario to use on actions and validations later.
Each session data lives in scenario context, it means it can be available only in that scanrio.
For example, a register event can have parameters like
username, email, fullname, address, mobileno. You can save all these parameters into sessions and then in another action, even the incoming event is different like forgot password which only has username parameter, you can generate email action which uses
fullname, address, mobilno.
Tip: If you need to use data in multiple states, use sessions
Session creating is really simple. Just go scenarios page and select the scenario you want to add session.