Ethernet is a reliable standard for Internet connectivity. If you don't need Wireless (and don't want the headache of wireless either), then Ethernet can be a very good option.
No antennas, no SSIDs, no passwords, plug it in and forget about it.
While there are a few Feathers that have built-in 'Ethernet support' they all need a PHY interface anyways and it's about the same price as the W5500 chipset we use. So we just went with this, which is a well-known (or, at least, infamous) chipset. And, yes, you can use it with our WiFi Feathers to create a Feather with dual-connectivity options (or a very slow and silly WiFi bridge)
This Wing uses the SPI pins and a CS pin, you can cut the jumper to re-assign the CS pin. You can use with other SPI-based wings (displays, music, radio, datalogging, etc) just make sure there's no pin conflict for the CS pin.
This Wing does not support active Power-over-Ethernet (PoE), but you can easily hook up a passive PoE configuration with a passive injector, a 5V power adapter, and a 2.1mm to MicroUSB cable. See the tutorial page for more details
Nowadays, many people have WiFi set up because they won't want a fat ethernet cable running to their project. This is a featherWing with an ESP32 co-processor on it for exchanging data via WiFi.
Give your Feather project a lift with the Adafruit AirLift FeatherWing - a FeatherWing that lets you use the powerful ESP32 as a WiFi co-processor. You probably have your favorite Feather (like the Feather M4) that comes with its own set of awesome peripherals and lots of libraries. But it doesn't have WiFi built in! So let's give that chip a best friend, the ESP32. This chip can handle all the heavy lifting of connecting to a WiFi network and transferring data from a site, even if its using the latest TLS/SSL encryption (it has root certificates pre-burned in).
Having WiFi managed by a separate chip means your code is simpler, you don't have to cache socket data, or compile in & debug an SSL library. Send basic but powerful socket-based commands over 8MHz SPI for high speed data transfer. You can use 3V or 5V Arduino, any chip from the ATmega328 or up, although the '328 will not be able to do very complex tasks or buffer a lot of data. It also works great with CircuitPython, a SAMD51/Cortex M4 minimum required since we need a bunch of RAM. All you need is an SPI bus and 2 control pins plus a power supply that can provide up to 250mA during WiFi usage.
We placed an ESP32 module on a FeatherWing with a separate 3.3V regulator, and a tri-state chip for MISO so you can share the SPI bus with other 'Wings. Comes fully assembled and tested, pre-programmed with ESP32 SPI WiFi co-processor firmware that you can use in CircuitPython to use this into WiFi co-processsor over SPI + 2 pins. We also toss in some headers so you can solder it in and plug into a doubler, but you can also pick up a set of stacking headers to stack above/below your Feather.