Bluetooth was invented in 1994 by Ericsson to replace wired cables for data transfer between electronic devices using short-range radio links. It allows inexpensive wireless connection of multiple devices without direct line of sight. Bluetooth devices can form piconets of one master device connected to up to seven slave devices or scatternets of multiple interconnected piconets for longer range communication. While convenient, Bluetooth has disadvantages like increased security risks and limited range.