what does * do for directive in angular code example

Example 1: angular directive output

// just use it normal
@Output() itch:EventEmitter<any> = new EventEmitter();

//and call in html
<div appCollar (itch)='scratch()' >

Example 2: user defined directives in angular 7

<p [ngStyle]="{`THE CSS YOPU WANT TO ADD`}"> I am an Attribute Directive</p>