3.2.2.1. Session: Introduction to Chain of Blocks

Data Record in Decentralized Systems (15 minutes)

Begin by recapping the key concepts from the previous module on decentralized coordination.
Present students with a problem scenario: In a blockchain network, multiple nodes must share and update common records or data. Emphasize the importance of these common records for coordination and trust among nodes.
Ask students to share examples of data storage and types of data storage in everyday life (e.g. cloud storage).
Encourage students to empathize with the challenge of maintaining consistency and trustworthiness when multiple nodes require access or update of common data.
Pose questions for discussion:
- "How do you think nodes in a decentralized network should handle common records?”
- "Is it practical for each node to have its own separate copy of these common records?”
- "Is it necessary for each node to have its own separate copy of these common records?”
Encourage creative thinking about how nodes can coordinate and maintain
shared records while upholding decentralization principles.

Defining the Blockchain Data Structure (15 minutes)

In this phase provide a concise explanation of blockchain data structure. ⇒ using slides (2.2-chain_of_blocks.pptx)
Explain that a blockchain comprises a chain of blocks, each containing a set of data records (transactions).
Emphasize that each block is linked to the previous one, forming a chronological chain of records.
Discuss why this structure is vital for recording and verifying transactions within a decentralized network.
Briefly explain the cryptographic link between blocks. Mention that each block contains a reference to the previous block's cryptographic hash, creating a secure and tamper-evident connection.
Emphasize that this linking mechanism ensures the integrity of the entire blockchain, as altering a single block would require changing all subsequent blocks.
Conclude the session by recapping the important concepts.