Short answers, pulled from the story.
Crimea is a peninsula in Eastern Europe on the northern coast of the Black Sea, almost entirely surrounded by the Black Sea and the smaller Sea of Azov. The Isthmus of Perekop, about 5 to 7 km wide, connects it to Kherson Oblast in mainland Ukraine.
Crimea is internationally recognised as part of Ukraine but has been under Russian occupation since 2014. A United Nations vote of 100 in favour, 11 against, and 58 abstentions affirmed Crimea as Ukrainian territory after Russia's annexation.
The largest city in Crimea is Sevastopol, and the population of the peninsula is 2.4 million.
On the 27th of February 2014, Russian forces occupied parliament, government buildings, and strategic points across Crimea following protests over the removal of president Viktor Yanukovych. The Russian-organised Republic of Crimea declared independence after an illegal, internationally unrecognised referendum, and Russia then annexed the peninsula.
The Crimean Tatars were forcibly expelled to Central Asia by Joseph Stalin's government in 1944 as collective punishment, on the grounds that some had joined Tatar Legions in the Waffen-SS during World War II. The act has been described as a cultural genocide, and many Tatars began returning after the Soviet Union fell.
Work on the Crimean Bridge across the Strait of Kerch began in May 2015, with the road bridge opening in May 2018 and the rail bridge in December 2019. At 19 km it is the longest bridge in Europe, surpassing the Vasco da Gama Bridge in Lisbon.
Crimea's Black Sea ports provide quick access to the Eastern Mediterranean, the Balkans, and the Middle East. Its strategic position made it the site of the 1854 Crimean War and a prize sought by Roman, Byzantine, Ottoman, Russian, British, French, Nazi German, and Soviet powers.