Bhavcopy is the file which contains all the information about various scrips being traded on an exchange. There are different bhavcopy for different types of exchange and market.
The bhavcopy shows the Open, High, Low and Close of the day as well as the total volume traded in a day.
You can...
You can have multiple Demat accounts. Demat account is just like a bank account. In Bank, you save money and demat you store the shares. So you can own more than two demat accounts and it is legal and you will not face any issue.
But only the disadvantage of having multiple demat accounts is...