Usage of Who vs that

Question

1. I know the man that came here.

2. I know the man who came here.

What is the difference in meaning between these two sentences?

Answer 1

There is no difference in this case.

Who is used when referring to people.

That is used to refer to people, animals, groups, or things, but who is generally preferred when referring to people.

Source: click

EDIT I also found a similar question on English SE: https://english.stackexchange.com/questions/11204/how-to-use-who-vs-that