Yes, there are different types of weed
The first step to knowing the differences is realizing there are differences in the first place -- so congratulations, you’ve completed the first step! The question of exactly why there are different types of cannabis is a little more complex, requiring a short history and geography lesson.
Cannabis is thought to have originated in Central Asia, but early trading routes brought it to India, where the rugged plants that were used to clinging to Afghani mountainsides soaked up abundant tropical sun instead. This caused a lot of changes in the way the plants look, as well as how they smell, taste, and affect the user.