If you’ve heard people mention it, but weren’t sure how to find it or use it, hopefully this video can be of use to you.
If you have no idea what it is, it’s a database of written Japanese that is intended to be used for research, but any random person can use it to do their own queries as well.
That’s a great way to use the corpus! Specially when learning to write. I can see it happening.
I sometimes use the database provided in this website (University of Tokyo). It goes to about 60,000 words listed in order of frecuency.
For me the only practical use so far it’s been for deciding if adding a flashcard for a word that might sound obscure from the start (mostly specific terminology) in my still too basic reading material.