Maize is a cereal grain that was domesticated in Mesoamerica and then spread throughout the American continents. It spread to the rest of the world after European contact with the Americas in the late 15th century and early 16th century.

While some maize varieties grow 7 m (23 ft) tall at certain locations, commercial maize has been bred for a height of 2.5 m (8 ft). Sweetcorn is usually shorter than field-corn varieties.

Maize cultivars grown in the temperate zone are considered day-neutral and flower after a certain number of days at > 50° F (10°C). However, maize cultivars from tropical locations typically have a short-day requirement for flowering and generally do not produce seed in the long summer days at higher latitudes.[2] The day-length requirement for flowering is controlled genetically and regulated by the phytochrome system.

The apex of the stem ends in the tassel, an inflorescence of male flowers. Each silk may become pollinated to produce one kernel of corn. Young ears can be consumed raw, with the cob and silk, but as the plant matures (usually during the summer months) the cob becomes tougher and the silk dries to inedibility. By late August the kernels have dried out and become difficult to chew without cooking them tender first in boiling water.

The kernel of corn has a pericarp of the fruit fused with the seed coat, typical of the grasses. It is close to a multiple fruit in structure, except that the individual fruits (the kernels) never fuse into a single mass. The grains are about the size of peas, and adhere in regular rows round a white pithy substance, which forms the ear. An ear contains from two to four hundred grains, and is from 10–25 cm (4–10 in) in length. They are of various colors: blackish, bluish-gray, red, white and yellow. When ground into flour, maize yields more flour, with much less bran, than wheat does. However, it lacks the protein gluten of wheat and therefore makes baked goods with poor rising capability.

A genetic variation that accumulates more sugar and less starch in the ear is consumed as a vegetable and is called sweetcorn.

Maize is widely cultivated throughout the world, and a greater weight of maize is produced each year than any other grain. While the United States produces almost half of the world's harvest, other top producing countries are as widespread as China, Brazil, France, Indonesia, and South Africa. Worldwide production was over 600 million metric tons in 2003 – just slightly more than rice or wheat. In 2004, close to 33 million hectares of maize were planted worldwide, with a production value of more than $23 billion.

World corn production in the year 2003 was 614.3 million tons while in year 2004 total world corn production is expected to be 642.6 million tons.

Major producing countries are United States, China, EU-25, Brazil, Mexico, Argentina and India. These countries accounts for around 80 % of total world corn production.

Major consuming nations of corn are China and USA.

There has been continuous increase in the consumption demand of corn mainly owing to increase in the demand from meat and starch sector. There is growing requirement of maize from poultry sector, which uses corn as feed.

Major importing nations of maize are Japan, Korea, Taiwan, Mexico, Egypt, Malaysia, EU and Colombia.

Among the major exporters of corn, USA stands first followed by Argentina and Brazil. China, South Africa, Ukraine are minor exporters, their share is very low. Only USA dominates the international trade of corn as an exporter.

India's maize production fluctuates between 10-14 million tons, with 80-90% of the production being in the kharif season.

Major states that contribute in Maize productions are Karnataka, Andhra Pradesh, Bihar, Punjab, Uttar Pradesh and Madhya Pradesh.

Around 6.5 million tons (roughly 50 % of total consumption) goes for feed use, primarily for poultry feed. Another 1 million tons of corn is used by the starch industry.

India is traditionally a maize importer, and Govt. permits a fixed quantity (determined each year) to be imported at 15%. Extra has to be imported at 50%.
However, in 2003-04, India exported around 3-5 lakh tons of maize, mainly to Southeast Asian countries.

Rising household incomes have shifted human consumption from maize to other cereals like rice and wheat. The rising incomes have also led to an increased consumption of meat, particularly of poultry, which has increased the demand for maize as feed.