With Bootstrap 4, wells, panels, and thumbnails have been replaced by cards. A card is a flexible container for many kinds of content. It includes customization options for headers, footers, and colors.

An example of a Bootstrap card component that contains an image, a title, and text content is illustrated in the following screenshot:

The markup required to generate the Bootstrap card is as follows:

<div class="card"> 
    <img class="card-img-top" src="~/img/skyline.jpg" alt="Card image cap"> 
    <div class="card-block"> 
        <h4 class="card-title">Chicago Skyline</h4> 
        <p class="card-text">Chicago Skyline At Night from Hotel 71 on Wacker
         Drive.</p> 
        <a href="http://publicdomainarchive.com/free-stock-photos-chicago-
         skyline-night-hotel-71-wacker-drive/" 
           class="btn btn-primary">Visit Source</a> 
    </div> 
</div>