This is an html block <table>   <thead>     <tr>       <th>Column 1</th>       <th>Column 2</th>       <th>Column 3</th>     </tr>   </thead>   <tbody>     <tr>       <td>Value 1</td>       <td>Value 2</td>       <td>Value 3</td>     </tr>     <tr>       <td>Value 1a</td>       <td>Value 2a</td>       <td>Value 3a</td>     </tr>   </tbody> </table> This is a ruby block # GET /blogs/1 # GET /blogs/1.json def show respond_to do |format| format.html # show.html.erb format.json { render json: @blog } end end