Obviously, there is a gap in experience here. Not to mention how much more educated an experienced trader is in comparison. Use of various risk management strategies, like at the very least setting an LS or TP. Controlling one's emotions is another area of discussion that weighs heavily in the favor of an experienced trader.
Easy. Experts are guys who have already mastered trading pscyhology techniques, then don't rush if they are not confident about the position, as well as they don't wait long to open it in case their analysis fully indicate that the price will grow/fall. Rookie traders have a sin to wait for a longer period until the price will reach its peak and then enter the deal and the price reverses. Everything is obviously because of their impatience, or lack of confidence, and the reason is lack of knowledge. I don't even touch upon the topic of leverage trading, as it's apparent that experts neatly treat leverage compared to novices.
The difference is in many things: in experience, in the ability to control your emotions and risks, in the approach to learning and self-development, in the quality of a trading strategy or trading plan, in the presence or absence of a system in trading. You also need to be able to choose a reliable broker that does not give out large bonuses with often impossible conditions to attract newcomers, but first of all provides favorable trading conditions and instant execution, such as fxopen.