Nespresso has two types of pods, classic and Vertuo. Classic is the pod that you would be familiar with, it has that same trapezoidial shape we all equate to pod machines. Vertuo pods on the other hand are wider and circular, and all around smarter.
Vetrtuo pods have what Nespresso has dubbed "Intelligent Brewing Technology". Each capsule has a barcode which the machine reads in order to determine the brew time, pressure, and water temperature to make the beans sing. These pods also come in seven capsule sizes allowing you to brew anything from an espresso shot, through to a carafe of coffee. All up these do make nicer coffee than the original Nespresso pods, but they are also an ecosystem lock in. Right now Vertuo pods are only available from Nespresso and there doesn't seem to be any sign of that changing soon, meaning you're at the whim of Nespresso's pricing and coffee selection.
Classic pods however are the more basic option that also come with more choice. While all these pods are brewed with the same pressure, temperature, and duration, the classic design is open to other manufacturers therefore there are thousands of coffee choices. Classic pods start at $0.82 from Nespresso, but you can buy reuseable ones and put your own beans in there bringing the price down to as little as $0.40 per coffee.