Many people said the gambling is just a game and another people said it is Investment. How do you think?

It depends upon the people's mind about gambling. You said it is just a game or investment. But for me, everyone has its own thoughts about this. Other people would gamble for its fun or they treat gambling as a fun activity. But some people treat gambling as serious money making. They do not know that they could involve a huge risk in it. Money that you are placing on an outcome that can produce or earn is defined as gambling.