In short, both companies are named "Apple". One is Apple Records. The other is Apple Computer Company. Recently, the two companies have engaged in legal action for the third time over trademark disputes. Apple Records believes that Apple Computer Company has ventured into the music market business (which inadvertently infringes on the trademark rights of Apple Records). However, Apple Computer Company argues that their company is merely providing a data transfer service. The crux of the dispute between the two companies lies here.
So, is MP3 a kind of music or a kind of data? Everyone might as well weigh in and offer an opinion.