Industry implies the transformation of existent materials into something new, into goods that are used as end-products themselves, or are utilized to manufacture more goods.
Industries can be classified into several groups. A brief account is given below:

1. On the basis of strength of Labour:
(i) Large-scale Industries
(ii) Medium-scale Industries
(iii) Small-scale Industries

2. On the basis of Raw Material and Finished Goods:
(i) Heavy Industries: Industries, which use heavy and bulky raw materials and produce products of the same category, are called heavy industries. Iron and steel industry presents a good example of heavy industries.
(ii) Light Industries: The light industries use light raw materials and produce similar finished products. Textile industry, electronics, fans, sewing machines are light industries.

3. On the basis of Ownership: Since the beginning of the planned development of Indian economy in 1951, industries are divided into the following three classes:
(i) Private Sector Industries: Industries owned by individuals or firms such as Bajaj Auto or TISCO situated at Jamshedpur are called private sector industries.
(ii) Public Sector Industries: Industries owned by the state and its agencies, like Bharat heavy Electricals Ltd. or Bhilai Steel Plant or Durgapur Steel Plant and Integral Coach Factory at Kapurthala are public sector industries.
(iii) Joint Sector Industries: Industries owned jointly by the private firms and the state or its agencies, such as Gujarat alkalies Ltd. or Oil India Ltd., fall in the group of joint sector industries.

4. On the basis of source of Raw Material:
(i) Agro-based Industries: Agro-based industries are those industries which obtain raw material from agriculture. Cotton textile, jute textile, silk, sugar, vegetable oil and paper industry are representative industries of agro-based group of industries.
(ii) Mineral-based Industries: The industries that receive raw material primarily from minerals such as iron and steel, aluminium and cement industries fall in this category.
(iii) Pastoral-based Industries: These industries depend upon animals for their raw material. Hide, skin, bone, horn, shoes, dairy, etc., are some of the pastoral-based industries.
(iv) Forest-based Industries: The industries which use forest products as their raw materials are known as forest-based industries. Paper, card-board, lac, rayon, resin, basket, etc. are examples of forest based industries:

5. Miscellaneous Industries: Industries can also be classified into the following categories:
(i) Village industries: Village industries are located in villages and primarily cater to the needs of the rural people. They usually employ local machinery such as oil extractor, flour-grinding and agricultural implements.
(ii) Cottage Industries: Industries which artisans set up in their own houses, work with wood, cane, brass, stone, etc., are called cottage industries. Handloom Khadi and leather work at the artisans’ house fall in this category.
(iii) Consumer Industries: Consumer industries convert raw materials or primary products into commodities directly used by the people. Textile industry, bakeries, etc., are some of the consumer industries.
(iv) Basic Industries: Industries, on which depend many other industries for their manufacturing processes, are called basic industries. Iron and steel industry and power generating industry are included in this category.
(v) Capital-intensive Industries: Industries requiring huge investments are called capital-intensive industries. Iron and steel, cement and aluminium are capital-intensive industries.
(vi) Labour-intensive Industries: Such industries which require huge labour force for running them are called labour-intensive industries. In these industries, labour is more important than capital. Shoe- manufacturing and bidi making, etc. are included in these industries.

Case studies

Iron and Steel Industry
• The location of steel industry is generally oriented to one or the other raw material sources, mainly iron ore or coal.
• However, recent technological developments in transport as well as processing, the use of scrap as raw material and agglomeration economies make market location, especially coastal, advantageous as well.
• The steel manufacturing centers all the world over, exhibit different sorts of locational orientation, viz,
a) Near coal deposits or iron ore mining areas, especially for inland location;
b) Near the major steel consuming centers; or
c) Sea port locations.
• Distribution
a) TISCO: Jamshedpur (Singhbhum district, Jharkhand),
b) IISCO (Burnpur, Hirapur, Kalti)
c) VISL (Bhadravati): (1923) on Bhadra River in Karnataka, Shimoga district
d) HSL-Bhilai: Largest plant in India established with Soviet assistance in 1959 in Raipur district of M.P.
e) HSL-Rourkela: established in 1965 with German assistance in Sundargarh district of Orissa.
f) HSL-Durgapur: established in 1962 with British assistance in Burdwan district of West- Bengal.
g) BSL-Bokro: established in 1972 with Soviet collaboration in Hazaribag district on the confluence of Bokaro and Damodar rivers.
h) Salem: Tamil Nadu
i) Vishakhpatnam: first integrated plant in the coastal area

Aluminum Industry
• Aluminium Industry in India is one of the leading industries in the Indian economy. The main operations of the India aluminium industry is mining of ores, refining of the ore, casting, alloying, sheet, and rolling into foils. India is the sixth largest producer of bauxite and ninth largest producer of alumina in the world.
• Locational Factors:
a) Aluminium is a raw material oriented industry as it grossly weight loosing.
b) Bauxite is the basic raw material in the aluminium manufacturing process. Bauxite is converted into alumina in alumina refineries.
c) Due to the high quality of bauxite and close proximity between bauxite mines and alumina refineries, the cost of bauxite to Indian producer is one-third of that of global producers.
d) Other raw materials used in the manufacturing process are calcine, petroleum, coke, caustic soda, aluminium fluoride, fuel oil, steam coal and anthracite coal.
e) The reduction of bauxite into alumina requires heavy amount of energy. Therefore, beside nearness to bauxite deposits, cheap availability of power is the major consideration in the location of this industry.
• Major Production Centers
a) Korba – (Bharat Al. Co. Ltd): Bauxite – Amarkantak – Phula- Kapahara region, Electricity- Korba Thermal Power Plant. Transport – Harwa- Nagpur Rail-line.
b) Renukoot (Hindustan All. Co. Ltd): set up in 1988 as one of the biggest unit. Bauxite – Bagni Hills (Bihar) and Amarkanatak Mts. Electricity – Rihand Dam.
c) Belgaum (Indian Al. Co. Ltd.): Bauxite – Chandgad, (Kohlapur Dist). Electricity – Sharavati Hep.
d) Alwaye (Indian Al. Co. Ltd.): both convert alumina into Aluminium metal. Alumina is produced at Muri from bauxite available at Bagru Hills.
e) Mettur (Madras Al. Co. Ltd.) T. N.: Bauxite – Sheravoy Hill. Electricity – Mettur HEP.
f) Ratnagiri (Bharat Al. Co. Ltd.) Maharashtra: Bauxite – Kolaba, Kolhapur, satara of Udaigiri Dhangarvedi region. Koyna HEP provides power.
g) Nalco (National Al. CO Ltd): established in 1981.