The outline property in CSS draws a line around the outside of an element. It's similar to border except that:
- It always goes around all the sides, you can't specify particular sides
- It's not a part of the box model, so it won't effect the position of the element or adjacent elements
Other minor facts include that it doesn't respect border-radius (makes sense I suppose as it's not a border) and that it isn't always rectangular. If the outline goes around an inline element with different font-sizes, for instance, Opera will draw a staggered box around it all.
It is often used for accessibility reasons, to emphasize a link when tabbed to without affecting positioning and in a differnet way than hover.
