title: What does dot mean in SQL query
body: <p>In the w3school tutorial for the SQL "JOIN command", the given example is:</p>
  
  <pre><code>SELECT Orders.OrderID, Customers.CustomerName, Orders.OrderDate
  FROM Orders
  INNER JOIN Customers
  ON Orders.CustomerID=Customers.CustomerID;
  </code></pre>
  
  <p>My question is what does the dots mean in <code>Orders.OrderID</code>, <code>Customers.CustomerName</code>, <code>Orders.OrderDate</code> and so on?</p>