@Reboot/Caio
As outofocus pointed out, there are a lot of different kinds of bananas. The one you described is just one of them. There are also the short squat red ones, and also bananas that look like the ones you get at your local supermarket, except they occur naturally.

The main difference between the ones that grow naturally in the tropics and the ones that are shipped overseas is that they are generally specific genetic strains that are bred for their ability to ripen over a longer period of time than normal, even after being cut from the tree.

These bananas are actually picked and shipped while still green, so to speak, so that by the time they reach their destination, they are almost already ripe, and are usually fully ripened within a few days of hitting the shelves at the store…

Most of the indigenous strains would have gone bad by the time they reached our shores…