What is a bonus issue?

What is a bonus issue? And BPCL shares having traded at six hundred (600) rupees and the company has recently declared 2:1 bonus issue. Amit owns five shares for BPCL but doesn’t understand what’s in it. 2:1 bonus issue is you will get two free share for every one share. With 100 shares of BPCLAmit will now get additional two hundreds shares take in his total to 300 shares because the number of shares as triple. the price of each share is now 1/3 of previous value so each price of prime infra shares 600 rupees before the bonus issue it will now be 200 rupees total number of shares Amit owns has increased from 100 to 300 the total value of investment remains the same so way did prime infra issue bonus share? To reward to investors and gain the confidence as well as at rack new investor. Now Amit understand what bonus issue.