Cassette

In 1958, following four years of development, RCA Victor introduced the stereo, quarter-inch, reversible, reel-to-reel RCA tape cartridge. It offered few pre-recorded tapes and despite multiple versions, the tape cartridge failed.

Dutch engineer Lou Ottens (June 21, 1926 – March 6, 2021) worked at electronics and technology company Philips. Out of irritation about the existing tape recorder, he looked into a way to shrink large reel-to-reel tapes into something more compact and less expensive. Ottens came up with the audio cassette, essentially a miniature reel-to-reel mechanism in an enclosure, which Philips introduced in Europe on August 30, 1963 at the Berlin Radio Show.

The world's first cassette player was made available by Philip in the US. in November 1964. By 1966 over 250,000 recorders had been sold in the US alone.

One of the first (portable) cassette recorders from Philips, the Typ EL 3302 (1968). By mib18 at German Wikipedia 

The cassette's popularity grew further as a result of portable pocket recorders and high-fidelity ("hi-fi") players, such as Sony's Walkman (1979). By  the early 1980s the sales of music cassettes exceeded those of standard phonograph records.

A December 13, 1986 survey showed cassettes outselling vinyl by two to one in the US. The industry forecast that the 7-inch single was on the way out.

In Western Europe and North America, the market for cassettes declined sharply after its peak in the late 1980s. In 1989 Britons bought 83 million music cassette tapes, but 20 years later, after the invention of the CD and the iPod, that had declined to just 8,443.

The last car to have a cassette deck come as standard was the Lexus SC430 in 2010.

In 2011, the revised Oxford English Dictionary announced it would be removing the word "cassette tape" from its Concise version, causing some media backlash. The term was removed to help make room for more than 400 new words being added to the dictionary.

Sony released a cassette tape in 2014 with storage capacity of 185 Tera-Bytes. That means the tape could contain over 64 million songs, or the storage on 11 thousand iPhones.

Source Wikipedia