I recently ran into network slowdowns at work and started researching possible fixes. That is when I learned about a WAN interface card which is a hardware component that connects routers to wide area networks more efficiently.
Think of it as a bridge that helps your local network communicate smoothly with external networks. After upgrading the setup the difference was noticeable with less lag during video meetings and faster file sharing between offices. It is interesting how such a small piece of hardware can have a big impact on overall network performance and stability in real world use.