Physical cartridges can be linked to your Cricut account through Design Space. Many image sets have been released in physical form as a plastic cartridge that you can insert into a Cricut machine to access the image content. There are also some image sets that have been released only in digital form. Some physical cartridges have been retired, but the digital versions may still be available for purchase on. Many cartridges exist in both physical and digital formats. Cricut uses the term 'cartridge' to refer to image sets in general. Cartridges (or Image Sets) are groups of images that are related by a theme.