Launching wizards is use to show the view of any project in Odoo and using an ir.actions.act_window record like above, but with an extra field src_model which specifies that in the context of which model the the action is available. The wizard will appear in the contextual actions of the model, above the main view. Because of some internal hooks in the ORM, such an action is declared in XML with the tag act_window.For example you can see below code.

<act_window id="launch_the_wizard" name="Launch the Wizard" src_model="context_model_name" res_model="wizard_model_name" view_mode="form" target="new" key2="client_action_multi"></act_window>

Note-Wizards use regular views and their buttons may use the attribute special="cancel" to close the wizard window without saving.