- Trading: It is called a way to get more money by trading cryptos, either by transferring between them or by providing exchange services.
- Investment: There are many cryptocurrencies with a good future, but I only recommend Bitcoin and Ethereum.
- Gambling: sometimes beneficial and sometimes detrimental. I don't recommend it at all (risk high)
Don't invest yet until you're able to understand the whole concept of cryptocurrencies and how volatile this market is.
There is a process before you can do that, however, you can start by buying bitcoin with around the smallest amount that you can test to see how it feels like owning it but you won't feel the fluctuations since it's just a small amount.
If you talk about advantages about this industry, well there's a long list of if like you can protect yourself from infation, manageable coins without the need of intermediaries, fast and easy transactions and secure.
Well as you state, yes trading and proper investing of your chosen altcoins is a must thing to do in this industry. But it varies on how expert you are and how you studied your chosen field. Gambling isn't for profits because there's no assurance on it.