A food web is a graphical representation of the consumed and the consuming organisms in the ecosystem. A link in the food web connects the predator and the prey. In this article the concept of the food web and its constituents is thrown light upon. A food web is also commonly known as a food chain, the food network or the trophic network. The ecosystem refers to the biological environment formed by these organisms.
The plants, animals, water, land and air are all parts of an ecosystem. In a food web, an arrow represents the connection between the prey and the predator. The arrow is directed on the organism towards which the biomass is transferred as a result of the consumption process. A food web differs from a food network in that, the network not only illustrates the connections but also shows the amount of energy and nutrients going from the body of the prey to the body of the predator.
The food web starts with the plants that manufacture food from water, sunlight, minerals and chemicals found in the soil. The plants also known as autotrophs, manufacture food material by a process called photosynthesis. Certain bacteria also manufacture food through chemotherapy. The autotrophs are consumed by heterotrophs. Heterotorphic organisms are of the following types namely herbivoric, carnivoric, omnivoric, detritivoric, scavenging and decomposing.
Energy is derived from the sun. It is incorporated into the food web and is transferred along the food network. At each stage of predation, 90 percent energy is lost through the process of organic excretion, body heat and motion and only 10 % is transferred. This results in the formation of the biomass or trophic pyramid. The flow of energy in the ecosystem is depicted by the food chain in which organisms are grouped and placed at trophic levels. A trophic level may have a single species, or a group of species forming an internal prey and predator cycle within themselves.
A trophic level starts with autotrophs and ends mostly with a carnivorous organism. The inverted pyramid phenomenon is observed when the energy manufactures like phytoplankton result in a large amount of biomass available to their predators. Alongside the food web, the pyramid of numbers denotes the number of organisms at each trophic level, usually the higher the trophic level the smaller the number. Ultimately there is a single organism at the top of the pyramid.
The food web and the food chain only serve as models for the actual biomass and energy transfer processes taking place in an ecosystem. The actual processes are very complicated. Victor Summerhaves and Charles Elton(1923) have shown the food chain comprising of plants, bacteria and animals of the Bear Island Ecosystem at Norway. Hardy in the following year depicted the herring and plankton ecosystem of the North Sea.
Food chain 
