What does the term 'Sensex' stand for?

Which stock exchange are the companies listed in the Sensex a part of?

What type of stocks primarily constitute the Sensex?

What calculation method is currently used to determine the Sensex?

What is a key requirement to start investing in the Sensex?

Which of these events had a significant negative impact on the Sensex?

What was the approximate lowest point the Sensex reached during the market crisis of 2008-2009?