Summary
To make an image responsive in Bootstrap, add the img-fluid class to it, like this:
<img src="my-picture.jpg" class="img-fluid" alt="">Details
The img-fluid class will make the image fit inside of its containing element, and will allow it to shrink in size when on smaller screens.
You can also add an img-thumbnail class to add a border around the image. It will look more like a photograph with this class applied to it.
<img src="my-picture.jpg" class="img-fluid img-thumbnail" alt="">Exercises
Recreate the HTML code from the Demo section in your index.html file. You can use the provided placeholder image or add an image of your own to this folder.