What are the changes after february …

The main causes which led to the February Revolution were
The First World War: Russia participated in the First World War on the side of the Allies. During the course of the war, Russian armies suffered heavy losses which  demoralised the people.

Grim economic conditions: The First World War had disastrous impact on the economy of Russia. While retreating from battle fields, the Russian army destroyed crops and buildings in the country to prevent the enemy from using them as resources. Destruction of crops and buildings added over 3 million refugees in Russia. People in Russia began to question the participation of Russia in the war.

Scarcity of essential goods: As the war was fought on, essential supply of grains and bread were diverted to war fronts to feed the soldiers. This led to the scarcity of essential goods in the market leading to riots among the people.

Industrial shortage: Industrial production declined in Russia as able-bodied men were sent to war front to fight in the First World War. Industrial equipment disintegrated more rapidly in Russia.

All the above conditions led to anger and unrest in Petrograd. Famines in the cities, further, led to the deterioration of the condition in Russia. When the peasants protested against the Tsarist regime, they were supported by the soldiers. This finally led to the downfall of the Tsarist regime.