A chainsaw is probably one of the most powerful of all cutting devices made by mankind in the 21st century. They are mostly powered by a gasoline motor that provides around 3 to 4 BHP, way more than even the largest circular saws. Moreover, since it is powered by gas and uses a belt system directly driven by a clutch plate, the raw power gets directly transferred onto the belt. If you take a look at lumberjacks who make use of large chainsaws then will notice just how difficult it is to hold one of these devices upright.
Furthermore, chainsaws with electric motors are now starting to provide 1 to 2 BHP for domestic applications such as felling fallen trees, cutting branches and preparing firewood. They are much easier to handle since they are slightly less powerful and being electric in nature come with the advantage of zero vibrations as is often seen in gasoline motors. You can compare the relative merits of gas powered chainsaws and electric motor powered chainsaws by looking at chainsaw reviews and weighing up the pros and cons of each type.