Consumer surplus
The difference between the amount that consumers are willing to pay and the amount actually payed
Producer surplus
The difference between the amount the producer is willing to supply and the actual amount they receive
Producer surplus on s+d curve
Difference below price and the supply curve to equalibrium
Consumer surplus on s+d curve
Difference above price and demand curve to equalibrium
Flat tax
A tax put in goods and services
A set amount not percentage, same amount regardless of income
Subsidies
Direct payments, tax breaks and other special assistance that government provide businesses to offset cost