DD-WRT is an open-source firmware designed for wireless routers and access points. It enhances the functionality of standard router software, allowing users to customize settings, improve performance, and add features like VPN support, advanced QoS, and network monitoring. By installing DD-WRT, users can unlock additional capabilities that are often limited in factory firmware. This includes better control over bandwidth allocation, enhanced security options, and the ability to create guest networks. Overall, DD-WRT provides a powerful alternative for those looking to optimize their home or office network.