One of them is the standard language of Japan which is used in document and writings and that is called "Hyojungo". While there is another language which is spoken by the general public of Japan and its citizens this language is called "Kyotsugo". So these are the 2 major types of the Japanese language.
Now government of Japan has worked out on many policies on Japanese language so the key differences of these 2 standard languages are getting finished. And Japan is going to have one common language for all in near future.We can make another division of standard Japanese language. That is the literary language of japan and it is called "bongo" while the second type is the oral language of Japan and that is called "kogo" they both have slightly different grammar rules and some small difference in vocabulary. So these are the types of Japanese language. I hope my answer is satisfactory.