A couple easy search questions (I hope)

What is the difference between "All" and "Books" as search options?  I can't figure it out. 

All is a ranked search of all books in your Library, including Personal, Cloud and Print resources. Other types of search are presented in Cards with rectangular frames, but they usually provide partial results with an option to get more. This is similar to Books > All Books > None with [match all forms], except for the cards.

All has no options, so cannot perform the Search for specific authors, below.

Is it possible to limit a specific search to the author of a journal article?

Usually. In a Books Search enter  type:journal author:Charlesworth  after clicking "All Books" or whatever is showing:

EDIT:  this will only find the editor. Just use type:journal

Couldn't one use journalArticle:(author:Charlesworth) ?

Indeed one can, thank you.

But it is often only the header with title/author that is highlighted together with some text up to the first subject heading.  So it is no good to search for words unless the whole 'journal article' is highlighted.

But it is often only the header with title/author that is highlighted together with some text up to the first subject heading. 

I use it so rarely I was unaware of that.  Sermons are what I use more frequently where usually the entire sermon is highlighted.