Can it capture HDMI from a modern console or camera?

No. It has RCA (phono) composite inputs only, so it captures standard-definition composite video. HDMI sources need a different capture device.

Will it work with a VCR or old camcorder?

Yes, that is its main use. Connect the composite video and audio outputs of the VCR or camcorder to the RCA inputs and record on your computer.

Does it come with recording software?

No software is included. You use your own capture program, such as OBS or the software bundled with your operating system.

What quality can I expect?

Standard-definition composite quality, limited by the USB 2.0 interface and the composite signal itself. Expect softness and some color bleed typical of composite video.

Does it need a power adapter?

No. It draws power from the USB-A port it plugs into.

Does it work on Mac and Windows?

It is a USB video capture device, so it depends on driver support in your operating system and capture software. Check compatibility with your setup before buying.