Img-fluid or img-responsive?

[IsabelleCrispim]

Tell us what’s happening:

  **Your code so far**

<link href="https://fonts.googleapis.com/css?family=Lobster" rel="stylesheet" type="text/css">
<style>
.red-text {
  color: red;
}

h2 {
  font-family: Lobster, Monospace;
}

p {
  font-size: 16px;
  font-family: Monospace;
}

.thick-green-border {
  border-color: green;
  border-width: 10px;
  border-style: solid;
  border-radius: 50%;
}

.smaller-image {
  width: 100px;
}
</style>

<div class="container-fluid">
<h2 class="red-text">CatPhotoApp</h2>

<p>Click here for <a href="#">cat photos</a>.</p>

<a href="#"><img class="smaller-image thick-green-border" src="https://bit.ly/fcc-relaxing-cat" alt="A cute orange cat lying on its back."></a>
 <a href="#"><img class=" img-responsive thick-green-border" src="https://bit.ly/fcc-running-cats" alt=""></a>

<p>Things cats love:</p>
<ul>
  <li>cat nip</li>
  <li>laser pointers</li>
  <li>lasagna</li>
</ul>
<p>Top 3 things cats hate:</p>
<ol>
  <li>flea treatment</li>
  <li>thunder</li>
  <li>other cats</li>
</ol>
<form action="https://freecatphotoapp.com/submit-cat-photo">
  <label><input type="radio" name="indoor-outdoor"> Indoor</label>
  <label><input type="radio" name="indoor-outdoor"> Outdoor</label>
  <label><input type="checkbox" name="personality"> Loving</label>
  <label><input type="checkbox" name="personality"> Lazy</label>
  <label><input type="checkbox" name="personality"> Crazy</label>
  <input type="text" placeholder="cat photo URL" required>
  <button type="submit">Submit</button>
</form>
</div>

  **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.190 Safari/537.36.

Challenge: Make Images Mobile Responsive

Link to the challenge:

freeCodeCamp.org

[MatchaCrisp]

I assume the lesson’s slightly dated, as img-responsive was in bootstrap 3, and img-fluid is bootstrap 4+. The difference is that since responsive images do not rely on display:block;, they have removed it from .img-responsive which becomes .img-fluid

In these challenges prob stick with whatever instruction says, but when building your own thing probably use .img-fluid and add display:block;separately if needed.