To view all active modules and enabled features in a NetSuite instance, navigate to Setup > Company > View Billing Information and review the "Billable Components" and "Add-on Modules" tabs.
You can also check Setup > Company > Enable Features to see which functional modules are toggled on.
Not sure what each one does? Our full list of NetSuite modules explains every module group and when it makes sense to add one.
Steps to View NetSuite Modules:
Billing Information: Go to Setup > Company > View Billing Information to see a list of all provisioned modules and licensed add-ons.

Add-on Module subtab: Click the Add-on Modules subtab to view all enabled NetSuite Modules

Enable Features: Go to Setup > Company > Enable Features. This page lists all major, licensed, and enabled modules (e.g., CRM, Inventory, Project Management).
Installed Bundles: Go to Customization > SuiteCloud Development > Installed Bundles to see third-party or custom modules installed in the account.
Manage Plugins: Go to Customization > Plug-ins > Manage Plug-ins to view specialized, activated, or deactivated functional plug-ins
