Yarn is generally better for flexibility and lighter applications, while metal is superior for strength and durability. Yarn is composed of fibers twisted together, making it flexible and suitable for applications requiring bending and stretching. Metal, on the other hand, is a solid material with high tensile strength, making it ideal for structural and load-bearing applications.

Yarn is often used in industries such as textiles, where its flexibility allows for the creation of fabrics and clothing. According to the Textile Industry Association, the global yarn market was valued at approximately $180 billion in 2020, driven by the demand for textiles in various sectors. Yarn's lightweight nature also makes it suitable for applications like ropes, strings, and other flexible items.

Metal, however, is preferred in industries like construction, automotive, and aerospace, where its strength and durability are crucial. The global metal market was valued at around $1.5 trillion in 2020, according to the World Metal Statistics. Metal's ability to withstand high loads and extreme conditions makes it the material of choice for these applications.

For instance, in the automotive industry, metal is used for the body, chassis, and other structural components due to its strength and resistance to deformation. In contrast, yarn might be used for interior components like seatbelts, where flexibility is more important than structural integrity.

In summary, the choice between yarn and metal depends on the specific application's requirements. Yarn is better for flexible and lighter applications, while metal is superior for strength and durability.