People are used to divide exchanges between centralized or decentralized, regulated or unregulated, let's forget all this.
There are exchanges which you can only use to buy or sell cryptos, the commercial exchanges, and then there are investment exchanges which want to keep your coins, because they propose you plenty of services for them.

Commercial exchanges are:

bitcoin.de
bitvavo.com
paxful.com

Investment exchanges are:

binance.com
coinbase.com
poloniex.com

A huge problem is that commercial exchanges are small low profit companies, whereas investment exchanges are making much more money, so some commercial exchanges are turning into investment exchanges. Kraken did that to give an example.

A commercial exchange is just like the currency exchange booth you find in all international airports. You exchange one currency with another. That's it. It's quick and safe. Use investment exchanges at your own risk.