What does it mean when someone says that person is really down to earth?

The online source states that a down to earth person is a practical and realistic person.

To me, it means a person who keep things in perspective. In other words, a down to earth person will put in mind all views before his or her opinion. He or she weights all alternative before deciding or taking action.

This person also thinks before speaking, second they do not judge. Seeing how the world evolves some people do not change their behavior or attitude.

Someone who sees and tells it like it is, without putting their own "spin"on it, and acts appropriately.

There are words you can put to this phrase. Sensible, solid, trustworthy, real, realistic, humble. Basically, the opposite of someone with their "head in the clouds".

The person is humble despite his/her achievements.