Herbicide(s), also commonly known as weedkillers, are chemical substances used to control unwanted plants. Selective herbicides control  specific  weed  species,  while  leaving  the  desired  crop  relatively  unharmed,  while  non-selective  herbicides  (sometimes called “total weedkillers” in commercial products) can be used to clear waste ground, industrial and construction sites, railways and railway embankments as they kill all plant material with which they come into contact.