title: what is the difference between curly braces and double quotes for tcl commands
body: <p>what exactly is different when double quotes are used instead of curly braces in tcl commands. For example:</p>
  
  <pre><code>regsub "$something" $var1 "$something2" var1
  </code></pre>
  
  <p>vs</p>
  
  <pre><code>regsub {$something} $var1 {$something2} var1
  </code></pre>
  
  <p>The question isn't limited to just regsub though. Even when assigning to a variable using <code>set</code> I don't really see any difference. </p>