Absolute:

• Individual - Exists when a person can produce more of a certain good/service than someone else in the same amount of time
• National - same as individual
• Looking at what's faster, more efficient

Comparative:

• Individual/National - When they can produce good/service at a lower opportunity cost than another individual or nation
• Only one nation can have the absolute advantage in one product
• Looking at lower opportunity cost

Input Problem vs. Output Problem (Comparative):

Input Problem - What can be produced using least amount of resources land or time.

• Chosen Item/Forgone Item

Output Problem - Deals with production

• What is given up/what is produced

• Both problems look at lower opportunity cost

In case you having trouble doing thee calulations..

https://www.khanacademy.org/economics-finance-domain/microeconomics/choices-opp-cost-tutorial/gains-from-trade-tutorial/v/comparative-advantage-and-absolute-advantage