Dial up modems were the standard way home computers connected to the internet in the 1990s and early 2000s, using telephone lines to exchange a sequence of tones, beeps and static known as a handshake. That noisy process became deeply familiar to a generation who waited through it daily. As broadband replaced dial up, the sound survived online as nostalgia and comedy, shared in memes about slow connections and pages that refuse to load, which is why younger viewers also recognise it instantly.