Every photographer makes decisions about file formats constantly, yet most of us operate on habit, hearsay, or whatever our camera defaulted to when we first pulled it out of the box. The problem is that choosing the wrong format at the wrong stage of your workflow can quietly destroy your editing flexibility, balloon your storage needs, break compatibility with clients and labs, or degrade your images in ways you won't notice until it's too late. This guide breaks down what each major format actually does under the hood, what it preserves, what it throws away, and when you should reach for each one across capture, editing, delivery, and long-term archiving.