Metre long strands of tape coated with a magnetic sensitive layer. The cassette tape is the most important thing in our lives at that time. It's been used to store voice, music and computer data. We do not mind it it takes ages to FFW and REV to the song or segment we will be rewarded with the music when it comes. Technology made life easier when features such as auto-reverse and auto music skip/search came into being. Even the double cassette deck which allows tape to tape duplication was THE things everyone wanted. Then came the walkman. Then came the CD which the cassette held out without a scratch but killed the vinyl record instead. Then came the CCD and the MD in the format wars which failed to capture the Cassette Tape crown.
Then came the MP3 tecnology which spawned MP3 players and the iPod. By then, almost everyone has a computer which allows easy dowloads. And the cassette tape played it last song on the last cassette player.