Ringtones are short tunes that play when mobile phones receive a call. The document discusses how users can now customize their ringtones by having songs converted into ringtones and delivered to their phone in under a minute. While phones come with default ringtones, it is now popular to download custom ringtones from the internet or order them for a small fee. A ringtone maker allows a user to select a part of a song and send it to their phone as a ringtone. The document encourages readers to change their ringtones if they are bored of the current one.