Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

HTML How to Make a Website Styling Web Pages and Navigation Make a CSS Image Gallery

parent element

What does it mean by making images fill a parent element?

css/main.css
a {
  text-decoration: none;
}

#wrapper {
  max-width: 940px;
  margin: 0 auto;
}

#logo {
  text-align: center;
  margin: 0;
}

h1, h2 {
  color: #fff;
}

nav a {
  color: #fff;
}

nav a:hover {
  color: #32673f;
}

h1 {
  font-family: Changa One, sans-serif;
  font-size: 1.75em;
  font-weight: normal;
}
img {
  width:100%;
  height:100%;
}

The parent element is whatever contains the image. So if you have something like a <header></header> with an <img src='' ''> in between, then that image is inside the header. The img height and width of 100% makes it fill the parent element.

2 Answers

Steven Parker
Steven Parker
231,169 Points

They mean "fill, but not go outside...". So they want you to establish a maximum width that won't exceed the enclosing element. Sizes expressed in percentages are always relative to the size of the parent element.

You don't need to worry about height, if left unset, it will follow the width to maintain perspective.

Oleg Polyakov
Oleg Polyakov
30,453 Points

Let's say:

<div>
   <img>
</div>

If I set the div's width to 300px and the image's width to 100%, the image will be no more than 300px, i.e it will 'fill' the parent element.