

Yes, but if you care about power efficiency then they really aren’t a great option. Most professional server hardware that you can get for a decent price uses significantly more power than an old mini computer or a cheap N100 PC. I own a proliant but rarely power it on due to the fact that I could rent an similarly performant VPS for 2x the power bill. Besides that many server CPU’s don’t have integrated GPU’s and will require additional hardware if you want to run something like Jellyfin.
Old PC’s and especially laptops (make sure to consider removing the battery though) make great homeservers. You can run dozens of services on old hardware.