Question: I am using primeng 4. Have added p-checkbox in my template and have also imported it to the corresponding ts file. But whenever the page is getting loaded on browser I get this error of - "'p-checkbox' is not a known element "

Answer: 
You should import `CheckboxModule` in you `app.module.ts`.

Example:

```
...
import {CheckboxModule} from 'primeng';
...

@NgModule({
  imports: [
    ...
    CheckboxModule,
    ...
  ],

  declarations: [InputOverviewExample],
  bootstrap: [InputOverviewExample],
  providers: []
})

```

[Plunker demo of the setup](https://plnkr.co/edit/A02otPj4OKCjl0X9qGAO?p=preview)
For PrimeNG v14, had to use this in the module file

```
...
import {CheckboxModule} from 'primeng/checkbox';
...

@NgModule({
  imports: [
    ...
    CheckboxModule,
    ...
  ],

  declarations: [InputOverviewExample],
  bootstrap: [InputOverviewExample],
  providers: []
})

```