What does the "DW" in the Brother HL-L2370DW model name mean, and what connectivity does it have?

The “DW” stands for Duplex and Wireless. It has USB 2.0 and built-in Wi-Fi (b/g/n) with Wi-Fi Direct support, but no Ethernet port. For a compact mono laser printer, the wireless focus makes sense — it’s designed for a desk, not a server room.