Producers: Producers are basically organisms that make their own food. They get energy from chemicals/and or the sun, and with the help of water, they convert that energy into useable energy in the form of sugar, or food. Plants are one very good example of a producer.
Consumers: Consumers are essentially organisms which receive energy by consuming other organisms. These organisms are commonly referred to as heterotrophs, which include animals, bacteria, and even fungi.
Decomposers: Decomposers are organisms that break down dead or decaying organisms, and in doing so, they carry out the natural process of decomposition.