A junk car (salvage vehicle) is one so damaged, it makes more financial sense to sell its parts than to try to repair it and apply for salvage title. In broad sense, the definition of a junk car is an unwanted car. It doesn’t run, and it really has no use.
Your car has fought a good fight but it just cannot go on anymore. Also buying and selling junk cars help keep them off the streets and create space at workshops etc