Trade means that you exchange your currency to cryptocurrency, or in simpler term, you buy bitcoin at a certain price. You then hold your crypto, analyze the movement of the prices and try to forecast. When you think that you are gaining already or the price of bitcoin went higher than when you purchased it, you can exchange it back to your local currency or simply means sell your btc. It is more than an action, it takes having the right mindset and emotions. Others buy and sell in a span of time, while others hold it for a long time. Learn your own technique. Good luck!