This document discusses different types of dyes. It begins with an introduction to dyes, noting that they are colored substances that bond to substrates and are often water-soluble. It then covers the main types of dyes including reactive dyes, which form covalent bonds; disperse dyes, which are used for synthetic fibers; azo dyes containing the R-N=N-R' group; sulfur dyes for cotton; and vat dyes which are insoluble but become soluble during the dyeing process. The document provides details on the characteristics and applications of each dye type.