A rally in the Parade Square in Warsaw, during Gomułka’s speech announcing reforms aimed at democratizing the political system

After 25 February 1956, when Nikita Khrushchev gave a speech to the delegates to the 20th Congress of the Communist Party of the Soviet Union about Stalin's mistakes and crimes, of murders committed on communists, the world behind the Iron Curtain could not be the same. A ferment started, full of criticism of Stalinism and demands of democratisation.

For the People's Republic of Poland, 1956 was a year of transition. Protests in June by workers in Poznań highlighted the people’s dissatisfaction with their current situation. The events set in motion resulted in the reformers' faction, led by Władysław Gomułka, taking power. After brief but tense negotiations with the Soviet Union, the Soviets gave permission for Gomułka to stay in control, and made several other concessions resulting in wider autonomy for the Polish government. For Polish citizens, this meant the temporary liberalization of life in Poland. Eventually, hopes for full liberalization were proven false, as Gomułka's regime became more oppressive; nonetheless, the era of Stalinization in Poland had ended.
Information about events in Poland reached the people of Hungary via Radio Free Europe's news and commentary services between 19 October and 22 October 1956. A student demonstration in Budapest in support of Gomułka, asking for similar reforms in Hungary, was one of the events that sparked the Hungarian Revolution of 1956. The events of the Hungarian November also helped distract the Soviets and ensure the success of the Polish October.

source: Wikipedia