What are the four properties inside @Module() decorator?
The four properties are: imports (other modules whose exported providers this module needs), controllers (controllers that belong to this module), providers (services/guards/pipes registered in this module's DI scope), and exports (subset of providers made available to importing modules).
The four @Module() properties:
imports — other modules whose exported providers this module needs.
controllers — controllers that handle incoming requests for this module.
providers — services, guards, pipes, and other injectables scoped to this module.
exports — providers (or re-exported modules) made available to any module that imports this one.
Example showing all four properties
Only providers listed in exports are accessible outside this module. Providers not exported remain private to the module.