What are these resistors on the USB Host data lines for?

[anon92864395]

Hello,
What are these resistors on the USB Host data lines for?
This is a schematic of Adafruit's Feather RP2040 with USB Type A Host

Adafruit Feather RP2040 with USB Type A Host

Specifically, I'm asking about resistors R17 and R18 on the schematic, which both have values of 22 Ohms
Here is a slightly better zoomed in version, note that R18 is kind of covered by other labels.

Thank you very much, and happy new year!
Apologies if I have omitted any important information, please tell me how to improve.

[jremington]

A much better place to ask would be the Adafruit forum, which is professionally staffed by people who design and build the equipment they sell.

[LarryD]

D+ And D- are differential inputs, 22 ohm resistors is for impedance matching termination.

[bfobferer]

Here is some supporting information

Series Resistors in PCB Design for USB Connections

[anon92864395]

Thanks, I’ll keep that in mind for future Adafruit related questions!

[anon92864395]

Oh, that (kind of) makes more sense now, thank you!

[anon92864395]

Thanks, this also helped!