It’s the type of cage you are seeing in the picture. It stands for Cubes and correx (or coroplast). They are metal grids which hold together using connectors and cable ties. The correx is a thick plastic sheeting which makes the base of this cage. C&c cages are fantastic as they are bigger than commercial cages you can buy from pet shops and can be made into any shape or size to fit any space.
You can buy them as complete kits from specialist companies with all the equipment you need, or source the grids and correx separately. While sourcing separately is possibly cheaper, if can sometimes quite hard to get the correx in some places.
If you’re in the UK, search for c&c guinea pig cages. The first company that comes up is the one I used. They provide everything you need for your desired size of cage. They come in varying sizes.
You will then also need to decide on bedding when using a c&c - most people use fleece on top of puppy pads or specially made liners.