struct net_device, is the main Linux Kernel network interface or network port data-structure. Each network interface entry whatever you find in user-space commands like ifconfig, ip link, ip addr, is actually a struct net_device data-structure Linux Kernel driver instance for that corresponding port. In fact every packet buffer instance managed by the Linux Kernel via struct sk_buff contains a reference pointer pointing to its corresponding TX/ RX interface struct net_device instance. Hence here is my multi-part video episode series and research on the struct net_device data-structure.
Refer:
Linux Kernel Source:
/include/linux/netdevice.h ↗
struct net_device data-structure ↗