RMS Titanic was a British ocean liner that sank on 15 April 1912 as a result of striking an iceberg on her maiden voyage from Southampton, England to New York City, United States. Of the estimated 2,224 passengers and crew aboard, 1,496 died, making the incident the deadliest sinking of a single ship at the time.

 Titanic, operated by the White Star Line. RMS Titanic was the largest ship afloat upon entering service and the second of three Olympic-class ocean liners built for the White Star Line. The ship was built by the Harland and Wolff shipbuilding company in Belfast.

Titanic was under the command of Captain Edward John Smith, who went down with the ship.

The first-class accommodation was designed to be the pinnacle of comfort and luxury. It included a gymnasium, swimming pool, smoking rooms, fine restaurants and cafes, a Victorian-style Turkish bath, and hundreds of opulent cabins.

Titanic had advanced safety features, such as watertight compartments and remotely activated watertight doors, which contributed to the ship's reputation as "unsinkable".

Titanic was equipped with 16 lifeboat davits, each capable of lowering three lifeboats, for a total of 48 boats. Despite this capacity of 48, the ship was equipped with a total of only 20 lifeboats. Fourteen were regular lifeboats, two were cutter lifeboats, and four were collapsible and proved difficult to launch while the ship was sinking.

 The British Board of Trade's regulations required 14 lifeboats for a ship 10,000 tonnes. Titanic carried six more than required, allowing 338 extra people room in lifeboats. When the ship sank, the lifeboats that had been lowered were only filled up to an average of 60%.

Titanic was 882 feet 9 inches (269.06 m) long with a maximum breadth of 92 feet 6 inches (28.19 m).

The ship's total height, measured from the base of the keel to the top of the bridge, was 104 feet (32 m). Titanic measured 46,329 GRTgross register tonnage and 21,831 NRTnicotine replacement therapy and with a draught of 34 feet 7 inches (10.54 m) and displaced 52,310 tons. All three of the Olympic-class ships had ten decks (excluding the top of the officers' quarters), eight of which were for passenger use.

The entrance to the First Class Grand Staircase and gymnasium were located midships along with the raised roof of the First Class lounge, while at the rear of the deck were the roof of the First Class smoke room and the Second Class entrance. Just forward of the Second Class entrance sat the kennels, where the First Class passengers' dogs would stay. The wood-covered deck was divided into four segregated promenades: for officers, First Class passengers, engineers, and Second Class passengers respectively. Lifeboats lined the side of the deck except in the First Class area, where there was a gap so that the view would not be spoiled.

Titanic propulsion was supplied by three main engines—two reciprocating four-cylinder, triple-expansion steam engines and one centrally placed low-pressure Parsons turbine—each driving a propeller. The two reciprocating engines had a combined output of 30,000 horsepower (22,000 kW). The output of the steam turbine was 16,000 horsepower (12,000 kW). The White Star Line had used the same combination of engines on an earlier liner, Laurentic, where it had been a great success. It provided a good combination of performance and speed; reciprocating engines by themselves were not powerful enough to propel an Olympic-class liner at the desired speeds, while turbines were sufficiently powerful but caused uncomfortable vibrations, a problem that affected the all-turbine Cunard liners Lusitania and Mauretania. By combining reciprocating engines with a turbine, fuel usage could be reduced and motive power increased, while using the same amount of steam.

The two reciprocating engines were each 63 feet (19 m) long and weighed 720 tons, with their bedplates contributing a further 195 tons.

They were powered by steam produced in 29 boilers, 24 of which were double-ended and five single-ended, which contained a total of 159 furnaces. The boilers were 15 feet 9 inches (4.80 m) in diameter and 20 feet (6.1 m) long, each weighing 91.5 tons and capable of holding 48.5 tons of water.

They were fuelled by burning coal, 6,611 tons of which could be carried in Titanic's bunkers, with a further 1,092 tons in Hold 3. The furnaces required over 600 tons of coal a day to be shovelled into them by hand, requiring the services of 176 firemen working around the clock. 100 tons of ash a day had to be disposed of by ejecting it into the sea. The work was relentless, dirty and dangerous, and although firemen were paid relatively well, there was a high suicide rate among those who worked in that capacity.

Both Olympic and Titanic registered Liverpool as their home port. The offices of the White Star Line, as well as Cunard, were in Liverpool, and up until the introduction of the Olympic, most British ocean liners for both Cunard and White Star, such as Lusitania and Mauretania, sailed from Liverpool followed by a port of call in Queenstown, Ireland. Since the company's founding in 1845, a vast majority of their operations had taken place from Liverpool. However, in 1907 White Star Line established another service from Southampton on England's south coast, which became known as White Star's "Express Service". Southampton had many advantages over Liverpool, the first being its proximity to London.

In addition, Southampton, being on the south coast, allowed ships to easily cross the English Channel and make a port of call on the northern coast of France, usually at Cherbourg. This allowed British ships to pick up clientele from continental Europe before recrossing the channel and picking up passengers at Queenstown. The Southampton-Cherbourg-New York run would become so popular that most British ocean liners began using the port after World War I. Out of respect for Liverpool, ships continued to be registered there until the early 1960s. Queen Elizabeth 2 was one of the first ships registered in Southampton when introduced into service by Cunard in 1969.