Sol-gel is a versatile and widely used technique for synthesizing inorganic materials such as ceramics, glasses, and nanoparticles. It involves the formation of a sol, which is a colloidal suspension of nanoparticles in a liquid, followed by the gelation of the sol to form a three-dimensional network structure. This process can be controlled to produce materials with specific properties such as porosity, hardness, and transparency. Sol-gel materials have applications in various fields including optics, electronics, catalysis, and biomedicine.