Trading is to invest your money in bussiness.If you buy the items in low price and trade it with higher price you earn money at a time.
Its not a gambling because u can earn in every items you buy.
Maybe you experience of no income but not at all times.
As you learn the process how to trade you can earn for every transactoin you make.so trading will not count as a gamling.
People who holds some skills will always prefer to invest their money in trading instead of going for gambling where the chances of making money are too low and no skills or strategies will help you out in gambling as your results will depend only on luck factor.