A RouterBoard is a line of low-power, highly configurable dedicated router hardware designed and manufactured by MikroTik.
While officially a registered trademark, the term has become a fully genericised trademark within networking and hobbyist communities, and is now widely used to refer to almost any small form factor, purpose-built router hardware regardless of manufacturer.
Unlike consumer wireless routers which are optimised for ease of setup, RouterBoards are built first and foremost for routing performance and flexibility. They ship standard with MikroTik RouterOS, and offer near complete low level control over every aspect of network behaviour.
A mid range RouterBoard will vastly outperform a much more expensive consumer router at routing, firewall and packet processing tasks, but almost never includes user friendly features like mobile apps, one click setup or automatic updates. They are very commonly modified with third party firmware such as OpenWrt by hobbyists.
RouterBoards are the de facto standard hardware for wireless internet service providers (WISPs), professional network installers and advanced home networking hobbyists.
Common uses: WISP infrastructure, advanced home networks, custom firewalls, site to site VPNs, low power always-on networking
Related terms: Router, RouterOS, MikroTik, Firewall, Gateway, VPN, OpenWrt, Wireless Router, Modem Router, x86 Router