Hair gel is a hairstyling product that is used to stiffen hair into a particular hairstyle. The results it produces are usually similar to, but stronger than, those of hair spray and hair wax, and weaker than those of hair glue.

Many brands of hair gel in North America and the United Kingdom come in numbered variants. Higher numbered gels maintain a greater "hold" on hair, while lower numbers do not make the hair as stiff and in some products give the hair a wet look. A category typically referred to as "ethnic" gels are designed and manufactured specifically for sculpting the hair texture common to African Americans. Ampro Industries is a common example of this category.

Some forms of hair gel include temporary hair coloring for the hair, including variants in unnatural colors associated with various subcultures, and are popular within the goth and raver subcultures.^{[citation needed]}

Cationic polymers are one of the main functional component of hair gel. The positive charges in polymer causes it to stretch, making the gel more viscous. Hair gels resist natural protein conformations and allow hair to be styled and textured. This is because the stretched-out polymer takes up more space than a coiled polymer and thus resists the flow of solvent molecules around it. The positive charges also bind the gel to the negatively charged amino acids on the surface of the keratin molecules in the hair. More complicated polymer formulas exist; e.g., a copolymer of vinylpyrrolidone, methacrylamide, and N-vinylimidazole.

Hair is a filamentous biomaterial, that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals, but is also found in other animals.

The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and fine vellus hair. Most common interest in hair is focused on hair growth, hair types and hair care, but hair is also an important biomaterial primarily composed of protein, notably keratin. In many human societies, women predominantly grow the hair on their head long while men cut theirs short.

The word "hair" often refers to two distinct structures:

Hair fibers have a structure consisting of several layers. Starting from the outside:

Each strand of hair is made up of the medulla, cortex, and cuticle. The innermost region, the medulla, is not always present and is an open, unstructured region. The highly structural and organized cortex, or middle layer of the hair, is the primary source of mechanical strength and water uptake. The cortex contains melanin, which colors the fiber based on the number, distribution and types of melanin granules. The shape of the follicle determines the shape of the cortex, and the shape of the fiber is related to how straight or curly the hair is. Asian hair typically has a round fiber and is quite straight. Oval and irregularly shaped fibers are generally more wavy or even curly. The cuticle is the outer covering. Its complex structure slides as the hair swells and is covered with a single molecular layer of lipid that makes the hair repel water. The diameter of human hair varies from 17 to 180 micrometers (0.00067 to 0.0071 in).

A gel (from the lat. gelu—freezing, cold, ice or gelatus—frozen, immobile) is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state. By weight, gels are mostly liquid, yet they behave like solids due to a three-dimensional cross-linked network within the liquid. It is the crosslinks within the fluid that give a gel its structure (hardness) and contribute to stickiness (tack). In this way gels are a dispersion of molecules of a liquid within a solid in which the solid is the continuous phase and the liquid is the discontinuous phase.

Gels consist of a solid three-dimensional network that spans the volume of a liquid medium and ensnares it through surface tension effects. This internal network structure may result from physical bonds (physical gels) or chemical bonds (chemical gels), as well as crystallites or other junctions that remain intact within the extending fluid. Virtually any fluid can be used as an extender including water (hydrogels), oil, and air (aerogel). Both by weight and volume, gels are mostly fluid in composition and thus exhibit densities similar to those of their constituent liquids. Edible jelly is a common example of a hydrogel and has approximately the density of water.

Benjamin Neil Reeves (born 19 November 1991) is an English professional footballer who plays for Southampton. He plays as a midfielder.

Having started out in the youth team as a left back, he has since been converted into an attacking midfielder.

On 21 September 2011, he made his debut for Southampton, playing the full 90 minutes in the League Cup third round match against Preston North End. He set up the first goal in a 2–1 win. He started once again in the League Cup, in a 2-0 defeat at Crystal Palace. His first league appearance came against Brighton, as a substitute.

He joined Dagenham & Redbridge on a month's loan in February 2012.