CSS Outline
CSS outline is just like CSS border property. It provides to draw an extra border around an element to get visual attention.
Example:
<!DOCTYPE html>
<html>
<style type="text/css">
.box {
background-color: #eee;
outline: 3px solid #6666ff;
border: 3px solid #66ff33;
padding: 5px 10px;
}
</style>
<div class="box">Welcome to I2tutorials</div>
</body>
</html>
OUTPUT:

Border :
It is not possible to apply various outline widths, styles, and colors for the four sides of an element while in the border.
Outline:
The border is a part of the element’s dimension but the outline is not the part of element’s dimension.
Outline offset:
It is used to create a distance between outline and border.
Example:
<!DOCTYPE html>
<html>
<style type="text/css">
.box {
background-color: #1a8cff;
outline: 3px solid #000066;
outline-offset: 6px;
border: 3px solid Lightgreen;
padding: 5px 10px;
}
</style>
<div class="box">Welcome to JavaTpoint</div>
</body>
</html>
OUTPUT:
