The mini PC has an RJ45 network port for a wired Ethernet connection, but most HP ProDesk 400 G4s, including refurbished models, do not generally have a built-in Wi-Fi card. It is therefore often necessary to connect via an Ethernet cable. However, it is possible to add a Wi-Fi connection using an external USB Wi-Fi adapter, as the PC has USB-A 2.0 ports that can accommodate this type of accessory. In short, Wi-Fi is not always built in by default, but you can use a USB adapter for Wi-Fi if you don't want to use an Ethernet cable.