How do variables work in workflows?

Variables store data for the journey. Variable Management (Settings) defines Local (per session), Global (across sessions for that user/workflow), and Constant (fixed) variables. System and Data Profile are built-in and read-only. In node config and API Management you insert variables with the format {{local:Name}}, {{global:Name}}, {{constant:Name}}, {{system:Name}}, {{dataprofile:Name}}. Use the Insert variable row or </> picker in text fields. The engine resolves these at runtime; Variable state (Settings) shows current global values without changing workflow JSON.