The Great Compromise (also known as the Connecticut Compromise) was a compromise between the Virginia Plan and the New Jersey Plan.
At the Constitutional Convention, there was a controversy over how seats in Congress should be apportioned. The small states wanted seats to be apportioned equally. They wanted each state to have the same amount of power in the Congress. This made sense for them because it would give them more power. New Jersey was a relatively small state and the New Jersey Plan proposed this sort of equal representation.
The large states, by contrast, wanted seats to be apportioned based on population. They felt that a state with more people in it ought to have more votes in Congress. Virginia was the biggest state in terms of population and so the Virginia Plan proposed representation based on population.
The Great Compromise set up a system in which there were two houses of Congress. Seats in the House of Representatives were to be apportioned by population. Seats in the Senate were to be apportioned on an equal basis with each state having two senators. This, of course, is the system that we now have.
The Great Compromise also known as the Connecticut Compromise was an agreement brokered in 1787 to guide the representation that the states would have in both the lower and upper houses. This agreement had to be reached because of the emerging differences as to how representation would be done among the different states with varying sizes and inputs.
The Great Compromise was a reconciliation between two plans with one seeming to favor the small states while the other seemed to work in the interests of the larger states. The Virginia Plan proposed that all houses be allocated representation that is proportional to their population with nominations and elections conducted in the different houses. The New Jersey Plan sought to protect the smaller states and proposed a single house with all states having equal representation.
The Great Compromise reconciled the two proposals by allocating two seats in the Senate for all states while in the House of Representatives representation was guided by population of the states.