It depends. An IP address is somewhat anonymous. From your access log, clicking on an individual access will pop up more information about that access. A hostname can sometimes be traced back to a dialup account, or a company (if you recognize the name of that company in the host name). Other things to look at are the "user agent", which reports the type of browser the person was using while that hit was made. This is a convenient way to tell if the hit came from a bot, or a person.
Can I find out more about someone from their IP address?