A gel is a soft, thickened mixture where liquid is held inside a network of molecules or particles. This network can be formed by starches, proteins, gelatin, or pectin, and the final consistency depends on factors such as concentration, temperature, pH, and added ingredients like sugar or salt. Dessert examples include soft gels, such as puddings and pastry creams, and firm gels, such as Jell-O and baked cheesecakes.