Which exchanges support cryptocurrencies & altcoins?

Good day, esteemed crypto enthusiasts. As a fellow aficionado of the digital currency world, I'm curious to inquire about the current landscape of cryptocurrency exchanges that offer support for both major cryptos and their lesser-known altcoin counterparts. With the ever-evolving nature of this industry, it's crucial to stay abreast of which platforms provide access to a diverse range of digital assets. Could you please elaborate on some of the leading exchanges that cater to this diverse demand, highlighting their key features, security measures, and perhaps even their geographical reach? Your insights would be greatly appreciated in navigating this rapidly growing field.