huobi, like several other top exchanges (binance, okex, etc.) is a crypto exchange with full features. It is possible to buy with fiat currencies and there are different types of trade such as futures, margin, spot and otc.
The security of this exchange is good and when we keep our cryptocurrencies, we do not need to worry about losing them. Also, huobi exchange support is both polite and responsive. I had a problem a few months ago and I was the cause of the problem and the problem was not from the exchange office, after asking for their support, they explained the matter to me well.