Short answers, pulled from the story.
The Second Vienna Award was an arbitration agreement signed on the 30th of August 1940 at the Belvedere Palace in Vienna, by which Nazi Germany and Fascist Italy transferred Northern Transylvania, including all of Maramures and part of Crisana, from Romania to Hungary. The territory covered 43,492 square kilometres with a population of 2,667,007.
Romania and Hungary could not reach agreement in direct negotiations at Turnu Severin, which broke down on the 24th of August 1940. The Romanian Crown Council minutes described the Axis proposal as communications with an ultimative character, leaving Romania no practical alternative to accepting the arbitration.
The award was signed by German Foreign Minister Joachim von Ribbentrop and Italian Foreign Minister Galeazzo Ciano as arbiters. Hungarian Foreign Minister István Csáky and Romanian Foreign Minister Mihail Manoilescu signed on behalf of their respective countries.
Hungarian troops committed several massacres during the occupation of Northern Transylvania in September 1940. In Treznea, official Hungarian records listed 93 dead on the 9th of September; in Ip, Lieutenant Zoltán Vasváry ordered the killing of 159 villagers on the 13th and the 14th of September; and in Nusfalau, 11 ethnic Romanians were killed on the 8th of September.
The Second Vienna Award was voided by the Armistice Agreement with Romania signed on the 12th of September 1944. Article 19 of the agreement declared the Allied Governments regarded the Vienna decision as void and that Transylvania should return to Romania. The 1947 Paris Peace Treaties reaffirmed the original Trianon borders.
Excluding the Szekely area, 127,377 Jews from North Transylvania were deported for extermination purposes, overwhelmingly to the Auschwitz death camp. Of that total, 19,764 returned; 107,613 did not.