For example, you have $1,000 and you want to trade 50x leverage
It means 50 multiply by $1,000 which is equals to $50000.
You will be able to borrow $50,000 with $1000 from an exchange that offers margin/leverage trading.
But you have to know that the more leverage you go the more risky the trade but also the more you can gain, it depends on the market, if the market favor your prediction, you will gain but if the market goes another way around, your asset/coin you used to borrow the large amount of coins will be liquidated.
For example, 100x leverage is riskier/or profitable than 50x while 50x is riskier/ or profitable than 10x and so on and the profit or loss depending on the market price of the coin you borrowed, if it increase in price you are favored and your collateral will not be liquidated but if otherwise your collateral will be liquidated.
For beginners, you can read more about it
https://www.binance.vision/economics/what-is-margin-trading