A Display Business Rule has access to the current, g_scratchpad, and GlideSystem objects, but not the previous object. The previous object is only available to Before Business Rules4. References: Business Rule API
https://docs.servicenow.com/bundle/tokyo-application-development/page/script/business-rules/concept/c_BusinessRules.html

An example of when an application might not use a Scheduled Script Execution (Scheduled Job) is when the application needs to run a client-side script at the same time every day. A Scheduled Script Execution is a server-side script that runs on a specified schedule and performs some action on the server or database. A client-side script runs on the user's browser and cannot be scheduled by ServiceNow. The other options are examples of when an application might use a Scheduled Script Execution, such as sending email reminders, running a clean up script, or querying the database for unassigned records. Reference: Scheduled Script Execution, Client scripts

The statement that is not true for Modules is that every Module must be associated with a table. A Module is the functionality within an Application Menu that opens a content page in the content frame or a separate tab or window. A Module can be associated with a table, a list, a form, a report, a script, or any other type of page.
For example, the Open Module under the Incident Application Menu opens a list of incident records from the Incident table, while the Overview Module under thePerformance Analytics Application Menu opens a dashboard page with various charts and widgets. The other statements are true for Modules. Access to Modules is controlled with roles, as each Module can have one or more roles specified in its definition that determine who can see and access it. Modules open content pages, as they are links to different types of pages that provide information and functionality to users. Every Module must be part of an Application Menu, as they are the second-level navigation options for Applications. Reference: Modules