The BEST or the Brihanmumbai Electricity Supply and Transport is Mumbai's public transport service and electricity provider. The government owned organisation, which was set up in 1873, operates one of India's largest bus fleets. Originally setup as a tramway company, it branched out into supplying electricity to the city in 1905, and later into operating buses in 1926. The BEST is run by the city's municipality as an autonomous body.
The bus transport service covers almost the entire city and extends its operations outside city limits. In addition to buses, it also operates a ferry service. The electricity division of the organisation is also one of the few electricity departments in India to garner an annual net profit. Until 1995, BEST stood for Bombay Electricity Supply and Transport. After the name of the city was formally changed from Bombay to Mumbai, this was also reflected with the adjustment to Brihanmumbai, which means "Greater Mumbai".