Brioche knitting is a family of knitting patterns involving tucked stitches, i.e., yarn over

Yarn over

In knitting, a yarn over is technique in which the yarn is passed over the right-hand knitting needle. In general, the new loop is knitted on the next row, either by itself or together with an adjacent stitch . The yarn-over may also be dropped on the next row, producing a longer stretch of yarn...

s that are knitted together with a slipped stitch

Stitch (textile arts)

In the textile arts, a stitch is a single turn or loop of thread or yarn. Stitches are the fundamental elements of sewing, knitting, embroidery, crochet, and needle lace-making, whether by hand or machine...

 from the previous row. Such stitches may also be made by knitting into the row below (equivalent to the slipped stitch) and dropping the stitch above (equivalent to the yarn over).

The tucked stitches may form a second layer of knitting in front of the first layer, resembling an array of arches or (seen upside-down) of fish scales.

Although warm and beautiful in texture, garments made from brioche knitting have the drawback that the tucked stitches are liable to get caught and be pulled out.

Brioche knitting may have originated in the Middle East

Middle East

The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...

. However, the term "brioche" seems to have derived from French slang for "mistake". The name might be a reference to the brioche dinner roll, which is formed of two pieces, one stacked atop the other.