I'm working with Angular material and I'm facing the following problem.

In the example [here](https://material.angular.io/components/tabs/examples), you can change the background using this code:

```
<mat-tab-group [backgroundColor]="backgroundColorToggle.value">

```

but for me, it didn't work.
Btw I'm not using the variable but just a string:

```
<mat-tab-group [backgroundColor]="primary">

```

In the end, I tried the following and it worked:

```
<mat-tab-group backgroundColor="primary">

```

In my own component, as an input parameter (`@Input()`) I can use both:
`<app-my-component [input]=..>` and `<app-my-component input=..>`

So what the difference between `[input]="value"` and `input="value"` and why in my component both worked and in Angular material it didn't.