FOMO is the impulse to enter a trade — usually late, after a big move has already happened — purely out of fear of missing further gains, rather than because it fits a planned setup. It typically results in chasing price at a poor entry, right before a pullback or reversal, since the move that triggered the FOMO is often already extended.
FOMO is a psychological bias best managed structurally: sticking to pre-defined entry criteria makes it much harder to justify chasing a trade that doesn't actually meet them.
Next step
Guide
Choosing a Trading Platform: MT4, MT5, cTrader and the Broker's Own
The platform decides which orders you can place, whether your stops survive a closed laptop, and how much you would have to rewrite to leave. What actually differs between the options — and the point where the platform stops mattering and the broker takes over.