The term lint free cloth is a common name for cloths made from non-woven fabric. This is effectively a man-made material that is manufactured from a sheet of fibres, bonded together into a web by heat. After this, the sheet material is rolled in large mill rolls then it is converted into a variety of products. Fibres such as polyester, polypropylene and viscose are widely used in non-woven products and often combined with wood-pulp when manufacturing wiping cloths.
Simply put, lint free means that no fibres get left behind on surfaces when wiping or polishing. This is handy when cleaning glass or metal for example. It is also useful in working or home environments where cleanliness is critical.