title: BehaviorSubject vs Observable?
body: <p>I'm looking into Angular RxJs patterns and I don't understand the difference between a <code>BehaviorSubject</code> and an <code>Observable</code>.</p>
  
  <p>From my understanding, a <code>BehaviorSubject</code> is a value that can change over time (can be subscribed to and subscribers can receive updated results). This seems to be the exact same purpose of an <code>Observable</code>.  </p>
  
  <p>When would you use an <code>Observable</code> vs a <code>BehaviorSubject</code>? Are there benefits to using a <code>BehaviorSubject</code> over an <code>Observable</code> or vice versa?</p>