title: Trying to declare a function, getting error TS2384: Overload signatures must all be ambient or non-ambient
body: <p>I am declaring a function say getValue.  Then I am defining this getValue.  But I am getting error as</p>
  <p><code>error TS2384: Overload signatures must all be ambient or non-ambient</code>.</p>
  <p>What does ambient overload signature mean? What does non-ambient signature mean?  How do I define a declared function without getting this error?</p>
  <pre><code>declare function getValue(key:string):any;
  
  function getValue(key:string):any{
      return key;
  }
  </code></pre>