A simple definition of biomass is material of recent biological origin.

A more complete definition of biomass is any organic matter that is available on a renewable or recurring basis including but not limited to dedicated energy crops, agricultural crops and trees, food and feed crop residues, aquatic plants, industrial, municipal and agricultural solid wastes, forestry residues, and other fundamental cellular structures such as sugars, starch, and lignocellulose. Biomass is primarily produced from water and carbon dioxide by the process of photosynthesis. Biomass is from sustainable natural resources and therefore they renew at such as a rate that they will be available for use by next and future generations.

Unprocessed biomass has few applications. Processed biomass opens many opportunities to capitalize upon what has been described as North America 's "middle east" of carbohydrate production capability. Some may have previously referred to this capability as the "world's bread basket."

Biomass has several current uses. An age-old use is animal feed - but most of use already knew that. Newer uses include the conversion of grains to biodiesel, ethanol, and textile fibers. These more advanced uses are being commercialized at corporate levels. For example, instead of using sugar to sweeten your soda pop, high fructose corn sweetener now constitutes a very high percentage of that market. Based on the above definition, both sugar (from sugarcane or sugar beets) and the corn are biomass. However, the commercial conversion or extraction of a sweetener from a starch exemplifies the current level of thinking of being able to find new uses for biomass. Fermentation of corn is used to make ethanol that is typically blended with petroleum gasoline to rely less on finite petroleum reserves. You may have already known this, but did you know that other fermentation processes produce the raw material to make fibers for textiles. Dupont's Sorona Ò polymer represents this technology and is currently being readied for production by a Dupont - Tate & Lyle at a plant in Louden, Tennessee (about 30 miles southwest from here at The University of Tennessee).

Instead of just processing the grain from a plant of crop into useable products, there is a nationwide effort to use the entire plant material. Plants generally consist of lignocellulose.