Template reference variables are basically used to create a reference to the input element that can be used later on in any template. It is also called the hashtag syntax because it uses a hashtag to create a reference to an element in a template.

BY Best Interview Question ON 18 Aug 2020

Example

<input #mobile placeholder="mobile number">
Here a reference has been created to get the value of the input like:
//mobile is the input element
<button (click)="callmobile(mobile.value)">Call</button>
The above example is a foolproof method to avoid using the ngModel or some type of data binding by a simple form not requiring much validation.