Short answers, pulled from the story.
The Age of Discovery, also called the Age of Exploration, was a period from roughly the 15th to the 17th century when seafarers from European countries explored, colonized, and conquered regions across the globe. It connected previously isolated parts of the world and laid the groundwork for globalization.
The Age of Discovery is dated to around 1418, when the Portuguese began systematically exploring the Atlantic coast of Africa under the sponsorship of Prince Henry the Navigator. It overlapped with the early modern period and the Age of Sail and ran into the 17th century.
Vasco da Gama reached India by sea, arriving at Calicut on the 20th of May 1498 after sailing around Africa. His fleet of four ships and about 170 men had left Lisbon in July 1497, and he returned to Portugal two years and two days after departure with 55 surviving men.
The Treaty of Tordesillas in 1494 divided the world between Portugal and Spain along a line drawn 370 leagues west of the Cape Verde islands. Portugal gained Africa, Asia, and eastern South America, including Brazil, while Spain received everything west of the line.
The first circumnavigation of the globe was completed when the ship Victoria returned to Spain on the 6th of September 1522. Ferdinand Magellan led the expedition until he was killed in the Battle of Mactan in the Philippines, and Juan Sebastián Elcano completed the voyage. Only 18 of the original crew finished it.
Europeans sought new sea routes largely to reach the valuable spice trade of Asia directly, bypassing the monopoly held by Venice and Muslim traders over Middle Eastern and Indian Ocean routes. Spices were among the most expensive goods of the Middle Ages, used in medicine, religious rituals, cosmetics, perfumery, and as food preservatives.
Two key technologies were the magnetic compass and advances in ship design. The compass, invented during the Chinese Han dynasty, reached Europe by the late 12th or early 13th century, and the merging of northern European and Mediterranean shipbuilding traditions produced the full-rigged ship and the caravel.