General Electric Company (NYSE: GE) is one of the largest conglomerates in the United States. Known to many retail shoppers as the maker of appliances and other products for the home, GE ranks as the seventh-largest company in the United States by market capitalization as of Dec. 31, 2015. The company maintains a very diverse business model that operates eight distinct lines of business: power and water, oil and gas, energy management, aviation, health care, renewable energy, transportation, and appliances and lighting. Until recently, GE also operated its financial services business, GE Capital, but is in the process of fully divesting itself of all subsidiaries under this segment.

Shareholders were richly rewarded in 2015 as GE continued its transformation back to a more pure industrial company. Its stock returned a total of 28% in 2015, ranking it as the fourth best-performing stock in the Dow Jones Industrial Average (DJIA). Financially, the company's lines of business delivered mixed results, with energy-related segments struggling amid falling energy prices. GE, however, is still a highly profitable company with all lines of business augmenting the bottom line. According to GE's fourth-quarter 2015 earnings presentation, the following are the company's eight lines of business ranked according to operating profit.

1. Power and Water

GE's power and water division was the company's biggest profit generator. It works to develop and implement systems and solutions that utilize resources such as wind, oil, gas and water to produce electric power. It sells items such as turbines and generators to commercial customers; and pumps, filters and treatment systems to retail clients. In the fourth quarter of 2015, this segment netted $1.682 billion in operating profit, representing 29% of the company's total.

2. Aviation

GE's aviation division is one of the leading providers of jet engines and related machinery in the world. The segment's products are used in commercial aircraft, military fighter jets, helicopters, tankers, bombers and surveillance aircraft. The aviation line of business is one of GE's fastest-growing segments and reported operating profit of $1.571 billion in the fourth quarter of 2015, which is 28% of the company's total.

3. Health Care

GE's health care business is a global outfit operating in five continents around the globe and provides technological solutions all across the health care space. Its technology appears in medical diagnostic equipment, patient monitoring systems, drug manufacturing equipment and devices such as magnetic resonance imaging (MRI), computed tomography (CT) and positron emission tomography (PET) scanners. Health care delivered $938 million in operating profit, or 17% of the company's total, to GE's bottom line in the fourth quarter of 2015.

4. Oil and Gas

GE's oil and gas line of business looks to provide the equipment necessary to assist energy companies in exploring, extracting, refining and distributing the world's natural resources. This part of the company manufactures drilling and production systems, compressors, reactors and auxiliary equipment. Despite overall energy sector weakness for most of 2015, GE's oil and gas division still managed to report operating income of $715 million in the fourth quarter of 2015, for approximately 13% of the company's total.

5. Transportation

GE's transportation segment is one of the company's smaller lines of business and delivers high horsepower diesel-electric locomotives for use in several industries such as mining, transit, marine and drilling. It also develops and manufactures energy storage and management solutions, a newer initiative that GE launched in 2012. In the fourth quarter of 2015, the transportation division reported operating income of $339 million, representing 6% of GE's total.

6. Appliances and Lighting

While GE is well known for its household appliances, the appliances and lighting division actually represents only a small percentage of GE's bottom-line profit. In the fourth quarter of 2015, just 4% of the company's total operating profit came from this area. This line of business sells and services major home appliances including refrigerators, freezers, ovens, dishwashers, microwaves, air conditioners, residential water filtration systems and water heaters.

7. Renewable Energy

The renewable-energy segment is getting increased focus at GE; this company area works on developing wind and solar energy solutions. Products from GE's renewable energy group such as wind turbines and solar panels are operating in 40 countries as of January 2016. While this segment delivered over 6% of GE's total revenue in the quarter, it reported just 1% of the company's operating profit at $56 million.

8. Energy Management

Energy management provides electrical products and systems used to distribute, protect and control energy such as power panels, breaker boxes and smart meters. This segment added the least to GE's bottom line in the fourth quarter of 2015. It reported $33 million, or less than 1% of the company's total operating profit, for the quarter.