Bicameral legislation based on population rather than each state getting one vote. Three branches of government, but Legislative was the most powerful because it could chose the representatives for the other branches. Larger states supported because of their larger population.
Three Fifths Compromise
Each state had equal representation and had one vote and the plan also wanted a unicameral system with one section of Congress, going back to the Articles of Confederation system.
The Articles of Confederation gave each state one vote, regardless of size. Although Pennsylvania had a much greater population than New Jersey, they still only got one vote. To amend the Articles, the votes had to be 13/13 states to pass the amendment.
Slave states wanted more representation of their population, so they decided to allow for each 5 slaves, 3 people were represented for appointing representatives for the House.
The Connecticut Compromise gave each state equal representation with the Senate and proportional representation based on population in the House of Representatives. This combined the main points from the New Jersey Plan and the Virginia Plan
The Electoral College was created to avoid the direct election of the President and a compromise to give a bit of extra power to smaller states. This created a system that ensured only qualified persons were elected.