There is no description for these tags, are they referring to the same thing? If so then should they be merged? sleep-mode would appear more popular, although to be honest I prefer the shorter sleep and personally I never use the term "sleep-mode", always "sleep".
sleep-modeis when the device is sleeping (screen off and such) andsleepcould refer to other things. It appears to be used for a couple of questions about sleep patterns and alarms, sosleep-modewouldn't make sense there.sleepis not a good tag, someone's sleeping is not really relevant :Psleepis kind of an icky tag for that reason. It's easy to misuse, whereassleep-modeis easier to understand.sleep-modeis a better tagsleepandsleep-modereferred to the same thing (ie. computer sleep mode). To be honest, I never imagined that asleeptag, on a technical computer-related site, would refer to anything else. So, as stated, I would agree thatsleepis not a good tag in this respect. (Should it be removed?)sleep-modeavoids any ambiguity.