Declarations, providers. declarations / components are in local scope (private visibility) providers / services are in global scope (public visibility). SharedModules – You can import multiple common components in shared module and import shaedmodules. You also need to export those to use in other modules./////////////////////////////////////////////////////////////////////////////////////////////////////import { NgModule } from '@angular/core'; import { CommonModule } from '@angular/common'; import { FlexLayoutModule } from '@angular/flex-layout'; import { MaterialModule } from '@angular/material'; @NgModule({ exports: [CommonModule, FlexLayoutModule, MaterialModule] }) export class SharedModule {}