Leverage and margin
Leverage sets how large a position your balance can carry. At 1:10 a $10,000 balance can hold up to $100,000 of the market, and the position locks a tenth of its value as margin. The order ticket shows your buying power, and the account panel shows the margin in use and the margin level (equity divided by margin).
Free accounts trade at 1:1. Pro and Elite pick their leverage in Settings, Trading, for each kind of market: forex up to 1:100, gold up to 1:50, index cfds up to 1:50, crypto up to 1:5, stocks up to 1:4. Futures have no leverage setting, because their contracts already set the size.
If a position loses so much that your equity falls to 50% of the margin it needs, it closes on its own (a margin call). Higher leverage means a smaller move gets you there.
CTX has its own leverage of up to 5x for Pro and Elite, set on the CTX ticket while you have no position.