Short answers, pulled from the story.
The Vyborg, Petrozavodsk offensive was a 1944 Soviet military operation against Finland during the Continuation War. The plan called for a two-pronged attack from Leningrad via Vyborg to the Kymi river and across the Svir River through Petrozavodsk.
The main Soviet offensive began on the 10th of June 1944, when the Soviet 21st Army opened attacks on the Valkeasaari sector. Aerial assaults by the 13th Air Army occurred on June 9, one day before the ground assault started.
Soviet losses included over 5,000 soldiers killed or wounded on June 28 alone, with total Red Army casualties reaching 20,000 KIA, MIA, or WIA. Finnish forces lost 1,200 soldiers in battles such as Ilomantsi while suffering heavy artillery losses in other sectors.
The Soviet Karelian Front captured Petrozavodsk on the 29th of June 1944, after attacking the Olonets sector of White Karelia starting on June 20. The city was one of the main goals of the operation and marked a significant advance into Finnish territory.
Finland accepted peace terms because the offensive forced the country out of the war despite failing to breach all Stavka objectives. The Soviets offered reduced reparations totaling $600 million in September 1944 compared to earlier demands for unconditional surrender.