Article in English: Most people are more concerned about differentiating real leather from faux, or fake leather. But serious connoisseurs know that there are actually multiple grades of real leather, of which "Genuine Leather" is actually the second lowest grade. From most luxurious to least, the other types of real leather are:  Full Grain Leather Top Grain Leather Genuine Leather Bonded Leather Full grain leather only uses the very highest (closest to the air) layer of skin, which is the toughest, most durable, and most beloved. It is left unfinished, meaning it has completely unique characteristics, creases, and coloring. Because of the smaller amount of leather on the surface of each animal and the difficulty of working with full grain toughness, the price is understandably high. Be aware that some manufacturers will report something is "made with full grain leather" even if only parts of the chair or sofa are full grain. This is another reason why buying without seeing the good is rarely recommended. The most common "luxury" leather is top grain, which takes the layer of skin just below full grain and works it lightly to remove imperfections. It is smoother and more consistent than full grain, but easier to work as well, keeping the price down. While not as durable as full grain, it is still a strong, well-crafted leather. Genuine leather is made by stripping off the harder, more expensive grains from the top, then using the softer, easier to work leather underneath. It is not as durable as full or top grain, but it is much cheaper since it can be manufactured into a variety of goods with ease. Remember -- genuine leather is a specific grade, not the phrase for real leather. If you request genuine leather in a leather shop, they will have a specific type of product in mind. While bonded leather is still leather, it isn't an unbroken or regular piece of animal skin. Instead, the shavings from all the other leather grades are collected, ground up, and mixed with an adhesive liquid to make a piece of leather. Though cheap,...

Summary in Vietnamese:
Hiểu rằng "Genuine Leather" (da thật) là loại da thật được công nhận duy nhất trên thị trường. Da "full grain" dành cho các sản phẩm thượng hạng. Tìm kiếm loại da "top grain leather" (da lớp 2) để mua các món đồ có chất lượng tốt với giá phải chăng hơn nhiều. Biết rằng "genuine leather" (da lớp 3) thường có mặt da lộn hoặc có cảm giác như vậy. Tránh xa da "bonded leather" (da cán), loại da làm từ bột da và da bào thật trộn với keo.