Binance is a cryptocurrency exchange that allows you to trade in a variety of cryptocurrencies. One thing that Binance does not allow you to do, however, is deposit USD directly into your Binance account.
In order to deposit USD into Binance, you will first need to convert it into a cryptocurrency that is supported by the exchange. The most popular option for this is to use Bitcoin, as most exchanges support Bitcoin deposits.
Once you have converted your USD into Bitcoin, you can then send it to your Binance account by entering the address of your Binance wallet into the field provided on the deposit page of the exchange you are using. Once the transaction has been confirmed, the funds should appear in your Binance account and you will be able to trade with them as usual.
So, while you cannot deposit USD directly into Binance, it is still relatively easy to do so by converting it into a supported cryptocurrency first. This should not pose too much of a problem for most people, as Bitcoin is widely available and easy to buy.