Should have good knowledge for both investing and trading. But trading requires more intelligence and knowledge than investing ... I prefer investing to trading.
Well, both need a piece of good knowledge about things and superior intelligence to make a handsome amount of profit. You have to work more to excel in trading because you will need to learn analytical and technical skills. On the other hand, an investor also needs to brainstorm his ideas regarding the best investment options. Investment is a bit safer option than trading, but the profit margin is also less. Trading is riskier, but when looking at the profit margin and earning potential, I think it is better to take some calculated risk.
Both have risks and they need some knowledge. Investment has a wide variety whether it is business, land, property, or stock. Trading on the other hand is more about stocks, crypto, or forex. The advantage of this is that you can do it at home which is accessible unlike investing in some physical things where you'll need to be there to check it.
Having both is good because it means diversifying your investment and if both are successful then you'll be earning a profit. Just choose what risk you take and be good at it rather than not risking at all.