From a general perspective, skateboarding and snowboarding look relatively similar. Both sports are performed on a board. Tricks are possible with the usage of ramps and poles. Even the athletes who perform in these two sports often look kind of similar; the surfer bro phenotype is quite common.
The differences between these two sports are much greater than one being performed in the snow and other one being performed on solid ground. An entirely different skill set is required to perform at the highest levels of both skateboarding and snowboarding.
Skateboarding is generally seen as the harder sport to perform in. This might surprise some people as skateboarding seems to be a more common skill. Everyone probably knew at least one person at some point in their life who liked to skateboard. For some people a skateboard is a convenient and cheap form of transportation.
Snowboarding on the other hand looks very daunting. Flying off the slope of a mountain with nothing except a thin board attached to one’s feet is a sensation that most people tend to view as extreme. If one lives near an area that sees regular heavy snow, he or she may have gone snowboarding once or twice. The likelihood that they developed that experience into a skill is not very good however.
What makes skateboarding more difficult? The fact that the board is not attached to the feet makes a big difference. On a snowboard the board is attached making it easier to move the board without falling down. On a skateboard one wrong move will often result in the skater falling off of their board completely.
Both skateboarding and snowboarding are derivative of surfing. They require different skill sets to master, but both can be quite rewarding. The important thing to remember is that having considerable skill in one of these sports will not necessarily translate to having skill in the other. It is still a good start of course.