Understanding Distributed Ledgers
This module introduces the core concepts a developer must understand before building on Rootstock. Even if you are familiar with Ethereum, this serves as a unified foundation for the course.
What Is a Blockchain?
A blockchain is a distributed ledger maintained by a network of nodes that collectively agree on the state of the system. Instead of relying on a central authority, blockchains use consensus mechanisms to validate transactions.
Each block contains:
- A list of transactions
- A timestamp
- A reference (hash) to the previous block
- A proof of work or proof of stake (depending on chain)
Because each block links to the previous one, altering past data becomes extremely difficult—this creates immutability.
Why Distributed Ledgers Matter
Traditional databases rely on a central authority to maintain records. Distributed ledgers solve several key problems:
| Traditional Database | Distributed Ledger |
|---|---|
| Single point of failure | Redundant across nodes |
| Trust in authority | Trust in consensus |
| Centralized control | Decentralized governance |
| Mutable history | Immutable records |
Consensus Mechanisms
Blockchains achieve agreement through consensus mechanisms:
- Proof of Work (PoW): Miners solve computational puzzles to validate blocks. Bitcoin and Rootstock use this approach.
- Proof of Stake (PoS): Validators stake tokens to participate in block creation.
Rootstock leverages Bitcoin's Proof of Work through merge-mining, inheriting Bitcoin's security guarantees.
Summary
Before moving forward, ensure you understand:
- What a blockchain is and how blocks are linked
- Why distributed ledgers provide security guarantees
- How consensus mechanisms validate transactions
- The difference between centralized and decentralized systems