Distributed ledger concept in Blockchain / Solidity - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a distributed ledger?

A distributed ledger is a database that is shared, replicated, and synchronized across multiple locations or participants. It allows all participants to have the same copy of data without a central authority.

beginner

How does a distributed ledger differ from a traditional database?

Unlike a traditional database controlled by a central authority, a distributed ledger is decentralized. Multiple participants maintain and update the ledger together, increasing transparency and reducing single points of failure.

intermediate

What role do consensus mechanisms play in distributed ledgers?

Consensus mechanisms help all participants agree on the current state of the ledger. They ensure that updates are valid and prevent conflicting changes, keeping the ledger consistent and trustworthy.

intermediate

Name two common types of distributed ledgers.

Two common types are blockchain and Directed Acyclic Graph (DAG). Blockchain organizes data in blocks linked in a chain, while DAG uses a graph structure allowing multiple branches and faster transactions.

beginner

Why is immutability important in a distributed ledger?

Immutability means once data is recorded, it cannot be changed or deleted. This builds trust because participants know the ledger history is permanent and tamper-proof.

What is the main advantage of a distributed ledger over a centralized database?

A Requires less storage

B No single point of failure

C Faster data entry

D Only one participant controls it

Distributed ledgers spread data across many participants, so there is no single point that can fail or be attacked.

Which of the following is a consensus mechanism used in distributed ledgers?

A Centralized Server

B Random Access Memory

C Proof of Work

D Data Compression

Proof of Work is a common consensus mechanism that helps participants agree on ledger updates.

In a blockchain, data is organized in:

A Rows and columns

B Single documents

C Random files

D Blocks linked in a chain

Blockchain stores data in blocks that are linked together in a chain.

What does immutability in a distributed ledger mean?

A Data cannot be changed once recorded

B Data can be edited anytime

C Data is deleted after use

D Data is stored in multiple formats

Immutability means the data is permanent and cannot be altered after being added.

Which structure is NOT a type of distributed ledger?

A Relational Database

B Directed Acyclic Graph (DAG)

C Distributed Hash Table

D Blockchain

Relational databases are centralized and not considered distributed ledgers.

Explain what a distributed ledger is and why it is important in blockchain technology.

Think about how many people keep the same record without a boss.

Describe how consensus mechanisms help maintain the integrity of a distributed ledger.

Consensus is like everyone agreeing on the same story.