A thiol is an organic compound that contains a sulfur atom bonded to a hydrogen atom, represented by the functional group -SH. Thiols are similar to alcohols, which have an -OH group, but the presence of sulfur gives them distinct properties. They are often characterized by their strong, sometimes unpleasant odors, reminiscent of rotten eggs or garlic. Thiols play important roles in various biological processes. For example, they are involved in the structure of proteins, where they can form disulfide bonds that help stabilize protein shapes. Additionally, thiols are used in industrial applications, such as in the production of rubber and plastics.