Everybody needs a guide to dojo mats when buying mats. These days not too many people still refer to their training gyms as dojos. There was a time where there was a dojo on every corner. Not so many people use the old terminology anymore. That said there are still a lot of karate and judo dojos around. Any traditional Japanese martial art will still refer to their training area as a dojo. Most of them are also fitted out with dojo mats. Indeed very few dojos these days have no mats. Although there would be a few which would insist on training without dojo mats. Especially certain karate school.
When choosing dojo mats it is important to know what your needs are. It is true that a lot of dojo mats are tatami mats, but they are not the only option. Tatami mats tend to be used in judo schools. In judo school there is a lot of throwing and grappling on the floor. As you sweat on the floor it is good to have a mat which is easy to wipe down. This is where tatami mats come in as they are actually pretty easy to maintain and to keep clean. This convenience however come with a price which is reflected in the cost of buying these mats.
As a guide to buying dojo mays, the other option is EVA jigsaw mats. You will in fact find that most karate schools use EVA mats for their dojos. The same can be said about tae kwon do as well. In fact EVA jigsaw mats are probably the most popular training mats there is out there. It is no surprise that you can also find them in dojos.