Developing: Trying to get more links Exchange: Trading with others (I'll link to you if you'll link to me) Exchange is part of Developing, but developing can also include directories, articles and more.
Its nothing but, link exchanging is used to exchange links with one another,if u link with high PR sites,then you may have the chance to get more traffic within short period of time,whereas link developing is nothing but to get more links to your site.