To activate or deactivate an application in ServiceNow, you can adhere to the following procedure. Begin by accessing the ServiceNow instance and navigating to the System Applications section. Locate the specific application you intend to enable or disable and access its detailed settings. To enable the application, ensure that the designated checkbox or toggle switch is selected. Conversely, to disable the application, unselect the toggle option. Once the desired choice is made, save the modifications. By executing this process, you gain the ability to manage the availability and operational status of applications within the ServiceNow instance.