An ancient method of creating fabric by interlocking loops of yarn either by hand with knitting needles, or now by machine. Knitted fabrics tend to be made from natural, soft fibres such as wool and cotton, though it is possible to use paper, copper wire, plastic–anything that can be made into long enough fibres or lengths and worked with long needles or pins.
As a very basic summary, in hand knitting yarn is secured onto a needle (this is called casting on) and worked into a row of loops. Then, using a second needle, the yarn is looped back through each stitch and transferred to the second needle, thereby creating a second row. As this process is repeated, each row grows from the last, creating a piece of fabric. Knitting can be as much a straightforward skill as it can be complex, with endless variations in the number of needles used, types and combinations of yarn, stitches, etc.
Knit also refers to the most basic knitting stitch, in which the loop is worked with the yarn at the back of the work, creating a V shaped stitch–and the opposite of purl.