What is the difference between Bombay Stock Exchange and Nifty?

What is the difference between Bombay Stock Exchange and Nifty?
NSE: National Stock ExchangeBSE :BOMBAY STOCK EXCHANGESENSEX: Is the major index giving the market overview based on the median prices of all major Large Cap companies in India listed on the Bombay Stock ExchangeNIFTY: Is also an index of quality mid-cap and some large-cap companies listed in the National Stock Exchange.SENSEX includes 30 companiesNIFTY includes 50 companies
Bombay stock exchange (BSE) was established when trading was not yet computerised, etc. It was done in the trading ring. Physical presence was necessary. Hence it was limited in geographical area to Bombay. Only later it was computerised and one could trade from your office.
National Stock Exchange (NSE) was established in the 1990s. There was no trading ring. It was computerised and online. So trading could be done from all over the country. So was not limited by geographical area.