In the Distance and Far

In the distance (preposition) usually implies something that you can see away from where you are. Far (adverb) indicates something at a distance that you cannot see.

We live far from the university.

The lights in the distance twinkled like bright stars.

Note:

They traveled to far-away lands. (far-away = far-off)

There was a far-away look in his eye. (far-away = neglectful)

I've read as far as the third chapter.

I'll walk with you as far as the post office.

So far the work has been easy, but things may change.

I trust you only so far (and no further).