Short answers, pulled from the story.
The Sea of Azov has an average depth of 7 metres and a maximum depth of 14 metres, making it the shallowest sea in the world. Its shallowness results from continuous sediment deposits of sand, silt, and shells carried in by more than 20 rivers, chiefly the Don and the Kuban, which together account for over 90 percent of the sea's total water inflow.
The Ottoman Turkish name Baluk-Denis, meaning Fish Sea, reflected the sea's extraordinary biological productivity. It was once the most productive fishing area in the Soviet Union, yielding typical annual catches of 300,000 tonnes, or about 80 kilograms per hectare of surface, compared with 2 kilograms per hectare in the Black Sea.
Peter I's first campaign in 1695, with 31,000 men and 170 cannons, failed after two unsuccessful assaults on the 5th of August and the 25th of September. The second campaign in 1696, combining a fleet built over the winter with an army of 75,000, succeeded: on the 17th of July 1696 the Turkish garrison surrendered. However, under the Treaty of the Pruth in 1711, Russia was forced to return Azov to Turkey and destroy the Azov fleet.
Between May and November 1855, British and French forces entered the Sea of Azov after capturing Kerch on the 12th of May, then attacked Taganrog on the 22nd of May. Despite fielding roughly 16,000 soldiers against fewer than 2,000 Russian defenders, the allied forces failed to take Taganrog, eventually withdrawing around August 1855.
The Crimean Bridge, opened in May 2018, spans the Strait of Kerch at a clearance too low for Panamax ships to pass through into Ukrainian ports. Russia has since been accused of using the bridge to interdict shipping through the strait, effectively restricting Ukraine's ability to move large vessels to and from its Sea of Azov ports including Mariupol and Berdyansk.
In antiquity it was called the Maeotis Swamp and was known by names including the Cimmerian Sea and the Bosporic Sea. The Maeotians themselves, according to Pliny, called it Temarunda, meaning Mother of Waters. Medieval Russians knew it as the Sea of Surozh. The Ottoman Turks named it Baluk-Denis, the Fish Sea. The modern name Azov likely derives from the Kipchak Turkish word asak or azaq, meaning lowlands.