title: AngularJS dollar sign $() usage
body: <p>I've been learning Angular and now I'm trying to understand a large piece of code that was given me, and it has a lot of <code>$()</code> in the code containing a variable inside and a method call <code>$(variable_name).method()</code> or even a CSS class inside, between double quotes <code>$(".class_name").method()</code>. </p>
  
  <p>I understand <code>$scope</code> well, but I get confused with the syntax I explained above. Can someone explain what is it? Thanks in advance. /Teo</p>
  
  <p>P.S.: The code is a directive, so I assume JS don't have this syntax except for the Angular framework.</p>