What is SEO for Firefox Measuring?

[Thomas L]

The edit function in the toolbar hasn't appeared, so I'm asking this question again with additional details.
What is SEO for Firefox Measuring?
I've been using SEO for Firefox for a marketing assignment, but I've having some trouble understanding what some of the things that it's measuring actually mean and I can't find any resources on the subject. Specifically I need to know about "Traffic Value" and "Twitter". I'm guessing that they're rankings, but I just can't figure what they mean. Does anyone have any ideas?
Thanks,
Tom

The button for SEO for Firefox has a drop down menu, in that drop down menu there is an option called "Lookup This Page". Selecting that option brings up a box entitled SEO for Firefox - Site Information.
The box is made up of two columns (with no visible divider), on the right side there are various bits of data, on the left side is what they are called.
There are two bits of data which I want to know about. One is called "Traffic Value", the other is called "Twitter"
What I want to know is what they are actually measuring, it is not clear to me what these numbers are meant to be representing.

I can double click it to see the source of the entry, but that hasn't lead to an explanation of what exactly this data measuring, which is what I'm asking.

[John K75]

It can tell you stuff like: how many back-links a site (or a page) have, how many times was it indexed, page rank, keyword density, who is the owner (unless it's blocked), if links are "do follow" or "no follow" and a few more things. All together its a good plug in.

[Andreas]

Firefox Browser add-ons such as SEO for Firefox from SEOBook and the SEO Quake toolbar. These both show the PR of the website in the SERPs below the result. These are useful when digging around but they don't really offer anything above and beyond the Google TBPR and PaRaMeter. Don't get me wrong I am a big fan of the SEOBook tools and encourage anybody to download these and try them out, but only useful in circumstances where you want to know the PR of a site before visiting.