To Get a phrase with this sort of outsized significance in vehicle society, "JDM" is an acronym for a reasonably tedious phrase: Japanese Domestic Marketplace. It refers to products built and supposed for sale and use in just Japan (i.e., not for export). This includes all the things from cars https://elevemotors.com/product/jdm-honda-cr-v-k20a-engine-for-sale/