Meteor JS : The if syntax in html files

The syntax is :

{{#if conditional}}

{{else}}

{{/if}}

Example :

{{#if isShowFavorite}}
    <a href="#" class="btn btn-default btn-xs pull-right favorite" role="button" >
        <i class="fa fa-heart-o fa-icon"></i>
    </a>
{{else}}
    <a href="#" class="btn btn-default btn-xs pull-right unfavorite" role="button" >
        <i class="fa fa-heart fa-icon"></i>
    </a>
{{/if}}