Difference between [ngClass] vs [class] binding

Answer 1

This is special Angular binding syntax

This is part of the Angular compiler and you can't build a custom binding variant following this binding style. The only supported are [class.xxx]="...", [style.xxx]="...", and [attr.xxx]="..."

ngClass is a normal Angular directive like you can build it yourself

ngClass is more powerful. It allows you to bind a string of classes, an array of strings, or an object like in your example.