Yep. But putting it in the CSS is better
It doesn't effect the images. It affects them.
However, it effects the border around the image.
No, it affects the border around the image. However, it effects an undesirable effect. xD (Unless there was no border previously? The example thing doesn't seem to work any more, so I'm not really sure what the situation was.)
There's no border for images, and then he used the CSS making the border. He wanted to remove the border again. So yes, effecting the border.
When linking somewhere with a image, a border is naturally placed around said image.
True!
But there isn't one when you're not linking! xD