The two main types of knots used in carpet weaving are symmetrical and asymmetrical knots, also known as Persian and Turkish knots.
The symmetrical knot, also known as the Turkish knot or Ghiordes knot, originates from Turkey where it was first used. It can also be referred to as the Turkbaff knot. In this knot, the yarn (shown in red in the illustration) is looped around both warps (light yellow) and a weft (blue) is placed between every row of knots. This knot provides a stronger consistency in the carpet and is often used for thicker carpets. It is commonly used in Turkey, the Caucasus region, and western Iran, as well as by Turkish and Kurdish tribes and in some European carpets.
The asymmetrical knot, also known as the Persian knot or Senneh knot, is sometimes referred to as the Farsibaff knot. This knot involves looping the yarn (shown in red) around one warp thread (light yellow) and leaving it loose under the other warp thread. A weft (blue) is placed between every row of knots. The asymmetrical knot allows for a higher knot density and more detailed designs in carpets. It is commonly used in Persian workshops in Iran, as well as in India, Turkey, Egypt, and China.