For the purposes of Google Analytics a conversion is any completed activity.
You tend to have two types of conversion. You have micro conversions and macro conversions. Think about a micro conversion as any small action that’s important to enable people to get to a macro conversion.
For example, on an e-commerce website your macro conversion will be the ultimate end result – someone buying, so they complete the transaction.
Your micro conversions will be things like someone clicking on a product description to find out more information, downloading a brochure, or emailing you for more information. So the micro goal completions are equally important as macro ones because they lead towards that end result.