title: What is the difference between a realtime database and a "normal" database?
body: <p>I'm researching some backend-as-a-service (BaaS) solutions for developing web applications, and I constantly see that <a href="https://firebase.google.com/docs/database/" rel="noreferrer">Firebase refers to their database as a "realtime database"</a>, while for example <a href="https://backendless.com/products/data-management/" rel="noreferrer">Backendless doesn't mention the phrase "real time" anywhere</a>.</p>
  
  <p>I understand that realtime means that the data is processed immediately, but I thought all databases did that? If I for example have a MySQL/SQLite/PostgreSQL database and insert data, I expect it to be available for retrieval within (milli)seconds later, and definitely directly after an "INSERT ..." query has been completed.</p>
  
  <p>Can someone shed a light on what is so different about the Firebase realtime database, compared to other BaaS services "normal" databases?</p>