The main raw material of both the glass fiber and the glass is the quartz sand, and their main chemical composition is all silicon dioxide. However, they are different in production processes, properties and applications.

Glass fiber is very thin diameter filaments, as thin as a few microns, about one fifth of human hair. Glass fiber can be woven into fiberglass textiles such as fiberglass cloth, tapes, rope or composite materials. Fiberglass products are very flexible, however, the glass is a solid structure in the shape of slab or sheet. It is a transparent and colorless object, and is very brittle and can be easily broken.

Although glass fiber and glass have the same raw materials and the same chemical composition, their contents of silicon dioxide are different, and their production processes also are different. Glass fiber contains 50%-60% silicon dioxide, while the glass contains 70%-75% silicone dioxide. Glass fiber is formed by drawing molten quartz sand or glass balls through centrifugal rotation or air jet to process into filament fibers. The drawn fiber bundles are twisted into fiberglass yarn which can be further processed into fiberglass textiles such as fiberglass cloth, tape, rope, etc. The glass fiber also can be processed into non-woven fabric such as fiberglass mat. Glass is mainly formed through high-temperature melting followed by rolling, blowing or float processes.

Fiberglass and glass have different performances. Glass fibers are continuous thin filaments, so they have high mechanical strength. They also have excellent corrosion resistance, heat resistance and insulation property, however, glass is a very low strength product. It is very easy to break. Glass also has the properties of heat resistance and corrosion resistance.

Fiberglass and glass have different applications. Glass fiber can be used as an excellent composite material. Fiberglass cloth and mat can be combined with various chemical resins such as polyester resin, phenolic resin, epoxy resin to make into fiberglass reinforced plastic (FRP). FRP material can be made into a series of FRP products such as FRP storage tanks, pipes, grilles, doors, swimming pool, automobiles, ships, aerospace parts, building materials, etc. FRP products are widely used in various industrial fields and in our daily life. Glass fiber textiles are also excellent insulating materials. They have the properties of high-temperature resistance, thermal insulation property, corrosion resistance, electrical insulation, etc. They can be made into welding blankets, fireproof curtains, fireproof clothing, removable insulation jacket and also can be used as the lining materials for chemical containers, chemical reactors and so on. They can be used as wrapping materials for chemical pipelines, electric motors, cables and various electrical equipments. Glass can be made into glass windows, doors, glass cups and various kinds of glassware. Glass is also  an excellent decoration and building material.