title: what is a controlId in react-bootstrap
body: <p>I was just going through the <a href="https://react-bootstrap.github.io/components.html#forms" rel="noreferrer">React-bootstrap form</a> what is the use of <code>controlId</code> is it similar to <code>name</code> we use in legacy form?</p>
  
  <pre><code>&lt;form&gt;
      &lt;FormGroup
        controlId="formBasicText" ----------------------&gt;&gt; what is the use?
        validationState={this.getValidationState()}
      &gt;
        &lt;ControlLabel&gt;Working example with validation&lt;/ControlLabel&gt;
        &lt;FormControl
          type="text"
          value={this.state.value}
          placeholder="Enter text"
          onChange={this.handleChange}
        /&gt;
        &lt;FormControl.Feedback /&gt;
        &lt;HelpBlock&gt;Validation is based on string length.&lt;/HelpBlock&gt;
      &lt;/FormGroup&gt;
    &lt;/form&gt;
  </code></pre>