When choosing a VPN for your home or business, you need to know the options available to you. Some are free, some can be costly, and some may not even work for your needs. Here's a review of the popular options at this time (Fall 2022).
WireGuard is the darling of the day. It's relatively new, uses modern encryption methods, supports IPv4 and IPv6, and can be self-hosted. Others have come up with ways to deliver provisioning via QR-codes, user authentication to OAuth2 providers, and built-in support to various open-source and commercial routers.
IPsec has been evolving since the 1990s and was even proposed as a way to secure IPv6 traffic early in its development. It supports multiple encryption ciphers, and has replaced proprietary VPNs deployed by Cisco, Fortinet, and other vendors. It has a primary use in securing site-to-site traffic between routers, but can also be deployed to end-users. If you're not already using a commercial-grade device, StrongSwan can be configured to implement it on a server / virtual machine; and OPNsense also supports deployment as well.
OpenVPN has been an old stalwart for years. It leverages TUN/TAP to connect systems to a common server, using pre-configured certificate and/or user authentication. It is available both as a commercial and open-source offering.
tinc-vpn has been around for two decades and is interesting because it can be built out as a peer-to-peer mesh topology, as well as virtualize Ethernet provisioning. It does rely on the TUN/TAP driver OpenVPN leverages (which is fine for Linux, but can be tricky on Windows), and it uses older encryption methods (which are slower than newer ones); but it can be deployed freely, and particularly useful when bridging OpenWRT routers.
ZeroTier can be best described as a merger of what WireGuard and tinc offer, but in a commercially hosted web interface and brokering service. It is technically open-source and has a free user tier; but there are limitations to both outside the paid version.
Windows Server has offered a number of VPN access methods over the years. As Microsoft Azure has matured, it appears they've shifted their focus from server-hosted VPN via DirectAccess, SSTP, PPP, etc; to a newer setup that leverages their cloud services. Internally, Microsoft has deployed IPv6 to a level superior to their IPv4 usage; and DirectAccess leverages it heavily; but their Azure offerings are still catching up.