Quick note to start- because Russia still used the Julian calender, the "February" and "October" revolutions actually happened in March 1917 and November 1917 respectively. For convenience I will stick to dates on the Julian Calender.
First, what each revolution produced
The February 1917 revolution produced a democratic, republican government, with a, defacto, seperation of powers between the Duma (Russia's elected parliament created after the revolution of 1905) and the Soviets, workers councils also formed during 1905 and later, which until 1917 had no real political power.
The main aim of the Provisional government was to hold elections to Russia's first powerful parliament, the Constiuent Assembly. The provisional government also instituted a number of reforms in it's brief tenure including the abolition of capital punishment, reaffirmed freedom of speech and of the press,
The October revolution produced the communist dictatorship the USSR laboured under for another 70 years. Lenin's government, as promised, transferred "all power to the soviets" and made them supreme abiters of decision making (though of course he would claim a lot of power for himself under a "dictatorship of the proletariat"). Lenin's government shut down the Russian Constiuent Assembly after it had met for only a few hours, ending any hopes of parliamentary democracy in Russia for another 70 years. Lenin also implemented War Communism and started the Cheka, a secret police who killed at least 12,000 people between 1917 and 1922.
To put it simply, February was a liberal revolution (if such a concept is possible) whereas October was a socialist revolution.
Another key difference was the base of support for each revolution.
February was a revolution with a broad base of support. Mass demonstrations in the street against the Tsar, the economic harships and possible German conspiracies involving the Empress led to riots, riots which the soldiers of the Petrograd garrison refused to put down. Mass defections and rioting in the streets rendered the Tsar's position untenable and he was forced to abidcate in favour of his brother, who also wisely refused the job. This revolution was violent, with over 1000 people being killed in the bloody overthrow of the Tsar.
This cannot be said of October. Contrary to Soviet propoganda, there was no broadbase of support for the October Revolution. It was Lenin and a group of his supporters (including Stalin and Trosky) grabbing power from a provisional government who had lost control of the army following the Kornilov affair (google it). It's more accurate to say that the provisional government dropped power than to say Lenin seized it. It is joked that more men died in Eisenstein's dramatic filmic recreation of the October Revolution than died during the actual event itself.
Put simply, February was a liberal revolution whereas October was a socialist revolution. However, far from the bloody struggle one might expect when hearing the word "socialism", Lenin seized power without a fight. Far from the benignity one might expect from hearing the word liberal, the Provisional Government was born in blood, off the backs of a disgruntled working class it never could quite win over.
The role of Women might also be evaluated. Women protesters, marching on International Women's Day (March 8th in the Gregorian Calender, February 23rd in Russia) started the February Revolution through their protests, which was also a protest against the governments harsh food rations. Women in October were amongst the last to defend the Provisional Government's headquarters from Lenin's coup, the other soldiers having either defected or deserted.