In which areas taxonomical aids are helpful?

In which areas taxonomical aids are helpful? Why taxonomic aids are used in these studies? Which different taxonomical aids are used by the biologists?

Taxonomical aids are helpful in various areas such as agriculture, forestry, industry and in knowing our bioresources.
All the above mentioned studies need correct identification and classification of organisms. Identification of organisms requires intensive laboratory and field studies.
Biologists use herbarium, botanical gardens, museum, zoological parks and taxonomical keys, while doing taxonomical studies.