I know Bill vs I know about Bill

[keannu]

I think 1 means I am in meeting relationship with Bill, while 2 means I have some knowledge or information about
him, but actually I don't see him. Is it hundred percent correct?

1.I know Bill.
2.I know about Bill.

 

[emsr2d2]

I think 1 means I am in meeting relationship with (We don't say that. Did you mean "I see him personally?") Bill, while 2 means I have some knowledge or information about him, but actually I don't see him. Is it a hundred percent correct?

1.I know Bill.
2.I know about Bill.

No. It's not that simple. It's perfectly possible to know Bill and to know about him. If you know him, then it is likely that you have met more than once. You might know him from some business meetings but not actually know any information about him, other that what he does as his job. You might know his name from emails and phone calls but have never met him. If the latter were the case and someone said "Do you know Bill?", you would probably answer "Oh, yes. I know Bill. Well, I've never met him but we've exchanged emails etc".