text: In drug discovery high-throughput screening, it is desirable to screen a drug target against a selection of chemicals that try to take advantage of as much of the appropriate chemical space as possible. The chemical space of all possible chemical structures is extraordinarily large. Most stored chemical libraries do not typically have a fully represented or sampled chemical space mostly because of storage and cost concerns. However, since many molecular interactions cannot be predicted, the wider the chemical space that is sampled by the chemical library, the better the chance that high-throughput screening will find a "hit"—a chemical with an appropriate interaction in a biological model that might be developed into a drug.
  An example of a chemical library in drug discovery would be a series of chemicals known to inhibit kinases, or in industrial processes, a series of catalysts known to polymerize resins.