From Wikipedia:
A quark (/ˈkwɔrk/ or /ˈkwɑrk/) is an elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei.
In a Few Words
The Quarks rating system is a zero-to-ten rating system aimed at being as objective and fair as possible.
In Some More Words and Numbers
There is a total of 11 categories being considered. The main categories are being evaluated for all products, giving more weight to certain items that are considered more important than others (e.g. General Performance vs. Ease of use). There is also optional categories that may apply to just some products. If they do apply, they are given certain weight and are included in the overall calculation. If they don’t apply, then the percentage of influence (i.e. weight) is shifted to the other categories.
In an effort to being objective and considering other excellent reviews, Amazon and Newegg ratings are taken into account if they are available for the product being reviewed. If they are not available or they are questionable (e.g. one dubious review associated to the product), then they are not taken into account and their percentage of influence is shifted to the main categories.
A graph like the one below will be shown at the end of each product review page. The number in the center represents the final rating number (in Quarks) and each colored segment in the circle represents a category being evaluated. Hovering over each segment will show both its description and its contribution to the final score. Keep in mind that this contribution is not a rating from 0 to 10, but the weighted representation of the rating for that category.
Thus, a product with a rating of 10 in all categories (assuming all apply), would show the following Quarks rating.