The most common type of knit is jersey, which is what most basic T-shirts are made of. Jersey fabric is made with a single needle that works approximately like knitting needles, putting together knit and purls in rows.

Jersey knit fabrics can be 100% cotton or blended with other fibers such as polyester or rayon.  100% cotton jersey is commonly used in t-shirt type of applications as it has a sturdy hand and wear with a minimal stretch.  Cotton jersey blend knit fabrics with polyester or rayon are very popular knits as they provide a more fluid drape and added stretch, making them suitable for a wider range of uses like tops, dresses, and more!

Characteristics of jersey:

It doesn't have a lot of stretch factor.
It usually doesn't recover very well after being stretched (unless it has spandex in it).
Right and wrong sides are different: Vertical knit ribs are shown on the right side, while you can see horizontal purls on the wrong side (see picture above).
When pulled, its edges tend to curl toward the right side (perpendicular to the grainline) and to the wrong side (along the selvedges).
It usually hangs quite well from your body, depending on weight and fiber content.