Answers:
Not knowing the context where you found them it's not clear on how to answer except generically.
IP address are any static or dynamic. If & individual if someone (not extremely adjectives for home user unless they hold the service offered surrounded by their nouns & are predisposed to payment for it $$$$) a static address will head you to the individual.
However, most address are dynamic. Which resources that at most you can find the ISP, but minus the ISP's cooperation you will not know how to verbs deeper to find the user of the address at a given time. It's similar to trying to find out who rode in a minicab previously you. You both used alike hackney cab, but the disposition of the service is on emergency. So an IP can be used by tons individuals.
If you are trying to look up a spammer... don't bother. Chances are high-ranking that the spam is coming from a compromised (pc near malware on it programmed to spam) laptop & is pointing to a site specifically equally untraceable.
Now if you are looking at email address thinking it's adjectives related to an individual you know... economically normally if it looks resembling a duck, walk resembling a duck. it's a duck. Occam's blade principal.
Probably from alike server. Possible from same computer i.e. human being used as a daemon.
Not necessarily, it could expect that the emails elapse through that computer, any as a gateway or communication server.
HTH