Simply put a pesticide can be defined as a pest killing agent. The term –cide comes from the Latin word “to kill”. In legal terms a substance used for controlling, preventing, destroying or repelling unwanted organisms is known as a pesticide. Why do we need to use pesticides? World population is increasing rapidly at the rate of 200,000 per day. Therefore the food supply must also increase accordingly. It is estimated that nearly 34% of the population in developing countries suffer from malnutrition. How could this be addressed? The agriculture has to be intensified through inputs in the forms of fertilizers, pesticides, mechanization etc. and higher yielding better performing varieties has to be used. This will lead to worsening of the general pest situation. The global crop yield looses due to animal pests, weeds and diseases. Pests cause quantitative losses as well as they affect the quality of the agricultural produce. Pesticides are widely used in the agricultural sector and in the public health programmes. Pesticides can be used as an effective and reliable means of controlling pests and diseases. Most demonstrate a fast activity and effective under diverse ecological conditions. Pesticides can be applied easily and readily available at an affordable price. Pesticides can be cla-ssified according to, target pest, effect on the pest and chemical identity. Classification by target pest Pesticide type —- Target organism Algaecide —- Algae Avicide —- Birds Bactericide —- Bacteria Fungicide —- Fungi Herbicide —- Plants Insecticide —- Insects Nematicide —- Nematodes Rodenticide —- Rodents There are three types of pesticides according to effect on pest, Antifeedant inhibits feeding while insect remains on the treated plant – insect eventually starves to death. Desiccant dries up the plant parts and insect and the repellent drives pest away from treated object without killing it. Pesticides can be divided into Organic and Inorganic according to the chemical identity. Inorganic compounds usually derived from naturally occurring elements. Because of residual persistence and high mammalian toxicity the use of almost all inorganic chemicals has been discontinued. Organic compounds or Botanicals are derived from plants. Neem extract, Nicotine, Rotenone are some examples. Apart from natural organic compounds there are synthetic organic compounds as well like Organochlorines and organophosphates. Even though the pesticides are so great there are lots of problems as sociated with the usage of pesticides. Development of pesticide resistance in plants and other organisms, Resurgence of pests and epidemics and the presence of residues in the environment are some of those. Online tutoring Australia, the latest educational tool makes use of the various research papers and articles available online to provide the latest knowledge for the students. There are plenty of articles and research papers on pesticide usage and health effects, available for online reference. Australian Pesticides and Veterinary Medicines Authority is one such organization which publish articles on pesticide usage in Australia.