In this post we will discuss about Design Manager in SharePoint 2013 designer. Also you can check my previous posts on:
Design View has been removed from SharePoint designer 2013. Rather Microsoft introduced another tool called as Design Manager which helps customers customize SharePoint sites in a wizard-like approach.
Developers work with a designer or a design agency to brand SharePoint. First, the developer receives the non-SharePoint branding assets (HTML, CSS, images etc) from the design agency. The design agency can create these files using any web design tool such as Dreamweaver or Microsoft Expression. The developer uploads the received files to SharePoint. Then, with a behind the-scenes automatic process, SharePoint-specific assets (*.master & *.aspx) are generated. This process repeats until the branding task is complete. Then the developer exports the branding assets and creates a package (*.wsp) to deploy the custom brand to the production farm.
Design Manager provides a snippet gallery from there SharePoint controls can be quickly added to the design. From the top ribbon you can add controls to it. When a new control is added, only HTML representation of the control is generated, so the design agency can see how the control looks in SharePoint, even if its tool sets don't understand SharePoint. When it sends the branding assets back, SharePoint ignores the HTML representations and renders ASP.NET and SharePoint controls.