Question 1: What is the smallest unit of Bitcoin called?

Question 2: Which cryptocurrency was initially created as a "joke" but has since gained significant popularity and market capitalization?

Question 3: What does the acronym DeFi stand for in the context of cryptocurrency and blockchain technology?

Question 4: What is a "hard fork" in the context of a blockchain?

Question 5: Which popular hardware wallet manufacturer is known for its devices like the Nano S and Nano X?