I certainly have the equivalent of folders on my gmail accounts. gmail just doesn't call them folders - it calls them labels, but they work pretty much the same. When I'm in Inbox, I click on 'More' and below appear two options - 'manage labels' and 'create new label'. The latter allows you to create a folder/label, and that appears in your Inbox listing. Then, you just drag email from your Inbox to the label you want.