Cation exchange resins are specialized materials used to remove positively charged ions, or cations, from solutions. They consist of small beads made from organic polymers that are charged with sodium or hydrogen ions. When a solution passes through the resin, the cations in the solution are attracted to the resin and replace the resin's original ions, effectively purifying the liquid. These resins are commonly used in water treatment, where they help soften water by removing calcium and magnesium ions, which can cause hardness. They are also utilized in various industrial processes, including chemical manufacturing and pharmaceutical production, to ensure the quality of the final products.