Why The Apparent Double Download Of PDF's ?

Probably I'm doing something wrong. Please tell me what.

I google for pdf documents and get some hits.
I click on a link to 'open in new tab' and the pdf opens in new tab.

It takes time to download but when done it's all there apparently. I can click from page to page with greater speed than if it's sending all the pages down from the web all the time.

Or that's what it looks like to me.

But then if I want to keep it on my computer I have to click the 'download' on the pdf doc menu bar.

And then it downloads slowly again and saves as the doc name I gave it. So now I have it.

But it looks to me like I downloaded it twice.

The first time into RAM maybe.

The second time on the Hard Drive.

Is this what happens?
Why must it be this way or must it not?

In Firefox-based browsers, one can configure the options to view the pdf file in the browser in a 'new tab' or to simply download the file without viewing the file in the browser.

How do you have your browser settings configured for pdf's?

thank you very much for that. it fixed the problem. :)