Short answers, pulled from the story.
Russia's occupation began in 2014, when it invaded and annexed Crimea and took de facto control of Ukraine's Donbas region during a war in eastern Ukraine. Ukraine's parliament defined Crimea as temporarily occupied territory in Law No. 1207-VII, passed on the 15th of April 2014.
As of 2024, Russia occupies almost 20 percent of Ukraine's territory. An estimated 3 to 3.5 million Ukrainians live under that occupation, and the occupied territories have lost roughly half of their population since the invasion.
On the 30th of September 2022, Russia announced the annexation of the Donetsk, Luhansk, Zaporizhzhia, and Kherson oblasts, despite controlling only part of the claimed territory. The UN General Assembly passed a resolution rejecting the annexation as illegal.
The United Nations Human Rights Office reports arbitrary detentions, enforced disappearances, torture, and suppression of peaceful protest and free speech in occupied Ukraine. OHCHR found Russia guilty of enforced disappearances and torture as crimes against humanity, and Human Rights Watch found it guilty of forcible conscription and forced displacement.
Ukraine's peace terms call for Russian forces to withdraw from all occupied territory. Russia's terms call for keeping the land it already occupies, plus the rest of the Donetsk, Luhansk, Zaporizhzhia, and Kherson oblasts it claims but does not fully control.
Ukrainians who refuse a Russian passport are denied healthcare, freedom of movement, public sector employment, and social security benefits. From July 2024, anyone in occupied Ukraine without a Russian passport can be imprisoned as a "foreign citizen."