Who is Swift making fun of in each of the books? Why? What is the significance of the order in which Gulliver’s journeys take place? How does each adventure build on the previous one

Obviously this is too large a question for this site.  However, in Lilliput, he is making fun of small-minded people and people who act in ridiculous ways to gain power.  By the time he gets to the land of the Yahoos, he is making fun of the horrible vices and faults of all humans.  In Brobdingnag, he satirizes the entire Engish people and their forms of government; in Laputa he makes fun of intelligence without common sense.