Have I used any words which some readers may not understand?

It will help the reader know, if not understand, what is going on.

Even in terms your readers understand it had little meaning.

I wonder how many readers understand what this means in human terms.

The reader cannot understand Soviet activities in the third world without some understanding of these changes.

Can a package help a reader understand a story better?

He meant that the readers, not having had the Vision, couldn't really understand his words.

The older articles still make a reader understand better the issues of the present day.

You need to ask whether your readers understand the background and the context of the subject.

I was surprised you failed to include this important information, which would help readers understand the situation.