IPsec VPNs provide a secure connection between devices over the internet, protecting data from external bad actors. They are commonly used in business to enable employees to access a corporate network remotely. IPsec stands for Internet Protocol Security and is a secure network protocol that encrypts and authenticates packets of data to provide secure communication. There are two modes of operation: Tunneling mode, which encrypts the entire data packet, and Transport mode, which only encrypts the data packet message. Using an IPsec VPN provides multiple layers of security by providing authentication and encryption for data packets. IPsec VPNs can be set up on various operating systems, including Windows, Linux, and OS X machines. They require high support costs, but offer a secure alternative to traditional VPNs like Twingate.