Imported ICR18650 Battery
The best battery depends on your application. A high capacity rating is good for long duration applications like in electric vehicles and flashlights. On the other hand, a high discharge rating is good for high power applications like in vaporizers and power-tools.
Sometimes the size of your batteries are important when building a pack or fitting them inside of a device. Weight is a good way to quickly check whether your batteries are authentic. Chemistry will tell you how safe the battery is, and what kind of protection circuitry you will need if any. Panasonic is the market leader, but Samsung, Sony, and LG all produce very high-quality cells.
An 18650 battery is a set of chemicals inside a protective steel case. Then PVC shrink wrap is applied over the steel case, which gives the 18650 its color. Some companies buy cells from large manufacturers like Panasonic, and rewrap it with their own custom-branded PVC tube.