Although solid, these polycarbonate materials bend so can cover a curved, hoop frame. Or they can be cut and used in sheets for straight walls. These materials usually last for at least 15 to 20 years before they begin to yellow and reduce the light coming through. Such glazings made specially for greenhouses, compared to those that may look similar from home stores, often are treated on the outside to resist the UV rays from sunlight, and treated on the inside to reduce condensation that can build up and drip in humid greenhouses.
Of course if you want a more decorative greenhouse, such as attached to a home or building ("lean to" greenhouse), you may consider glass. This is harder to construct and deal with, can break, and unless twin wall (similar to energy-efficient windows for homes) lets more heat out. Glass greenhouses tend to be more expensive, but maintained can last for decades. If you're handy with tools and building, you may want to construct your own home greenhouse. Otherwise you may want to consider just buying a "kit" with all you'll need. You can then buy accessories such as heaters and benches. Some kits even include these. If you'll be growing vegetables in the ground you may not even need benches. There are many suppliers of greenhouse kits online and in garden supply catalogs, even from some seed companies. These can be located with an internet search for "home greenhouses" or similar.
If buying a home greenhouse kit, some other considerations in addition to glazing type are where it is coming from--is it suitable for a northern climate, and what is the freight charge? You might even call the company and, through talking with them, see if they can provide answers to any questions, and judge their customer service (if you have technical questions once your greenhouse arrives it helps to have such expertise handy). They should be able to give you tips on the foundation needed for your greenhouse (often this is just wood anchored in the ground), and how to make your greenhouse more energy efficient if you'll use it during colder months.