The Kerensky offensive was the series of demonstrations carried out by soldiers and industrial workers unhappy with the provisional government formed just after, and as result of, the original Russian revolution of late February 1917.
In July these demonstrations led to the sack of the provisional government, and the setting up of another provisional government headed by Kerensky. That one did not last any longer and in October Lenin led the Bolsheviks in a bloodless coup and established the Socviet communist government whose tone and methods remained as the power force.