The tribulation is a period of time approximately 7 years in length starting from the signing of the middle eastern peace treaty and ending in the return of Jesus Christ to earth, called the Second Coming, which is also at the time of the battle of Armageddon.
It is a time specific to the Jews but encompasses all those left behind at the rapture who know about God and realise the course they have to take. Any one who apposes the regime of the Anti-Christ on the grounds that he is of the Devil and as such can not be followed. Devout Jew's and those who know the Bible will not bow down to him (many Jews and non-Jews will be taken in) and they will be chased and tormented by the system, put in place by the Anti-Christ. It will be a system of religious and political pressure designed to obliterate the Jewish race and anyone who speaks openly about Christ. The devil wants to destroy the race, which gave birth to Jesus and also who are his chosen race. The devil knows his time is short and so will with all fury, hunt down anyone who still believes in God and Christ, or like the Jews awaits his return.
This period will start out during the first 3.5 years relatively slowly but will gather momentum as time passes and the devils plans are thwarted one by one. The second half of the seven years will see, horrors that has never been seen before on earth. The witch hunts and Spanish inquisition will pale in comparison to what will take place. Anyone who professes to be a believer in Christ and the Rapture which took place will be hunted with the Jew. The Anti-Christ will have everyone tagged so they can not buy or sell without this tag or as it is called in the Bible the mark of the beast, as this tag will be a symbol that you are on the side of the Devil and are one of his.
If you are unfortunate to be living in this time and want to survive it will seem like the easy option is to 'go with the flow', to do as you are told and take the mark of the beast, the tag. This however may afford you some comfort in this world but for only seven years after which you will be judged for your actions and side you took during the time of tribulation.
If you want to 'survive' and I mean that in the spiritual sense of eternity your best course of action is to side with the Jew, the real devout Jew and help them to survive. The other course of action is to stand your ground accept Christ for who he is and believe in god. This will secure your future in eternity but unfortunately will cause your death in this world. It must be pointed out it may not be a pleasant death, but one necessary for entrance into an eternity with God. The culmination of this tribulation is the war fought between good and evil, when the sides of the devil try to destroy the side of God, in the battle of Armageddon.