What is Public Blockchain

A public blockchain is a blockchain network that is completely open and permissionless anyone in the world can read the transaction history, submit transactions, run a node, and participate in consensus without requesting permission from any authority. Bitcoin and Ethereum are the preeminent public blockchains.

DEFINING CHARACTERISTICS OF PUBLIC BLOCKCHAINS

Open Participation: No invitation required. Anyone can create a wallet (no registration, no identity verification at the protocol level), submit transactions, run a full node, and participate as a miner or validator. Access requires only an internet connection and compatible software.
Full Transparency: Every transaction ever recorded is permanently visible to anyone. The complete history of all 900+ million Bitcoin transactions is publicly accessible through any block explorer. While wallet addresses are pseudonymous (not directly linked to names), the transactions themselves are entirely public.
Decentralisation: No single entity owns, controls, or can shut down a public blockchain. Bitcoin is maintained by tens of thousands of globally distributed nodes following the same protocol rules, with no CEO, no company, no servers to seize.
Censorship Resistance: No one can block a valid transaction from being confirmed. There is no authority to call, no policy to appeal to, no compliance department that can freeze your wallet. A transaction conforming to the protocol rules will be confirmed by the network.

SECURITY THROUGH OPEN VALIDATION

Counterintuitively, public blockchains are often more secure than private ones because: every protocol rule is publicly auditable by security researchers worldwide, any attempt to alter the protocol requires convincing thousands of independent node operators to upgrade, and the attack surface is well-known vulnerabilities are identified and fixed through open-source development.

MAJOR PUBLIC BLOCKCHAINS

Bitcoin (BTC): Store of value, digital gold, most decentralised.
Ethereum (ETH): Smart contract platform for DeFi, NFTs, Web3.
Solana (SOL): High-throughput DeFi and gaming.
BNB Chain: Binance ecosystem applications.
Cardano (ADA): Research-driven smart contracts. Litecoin (LTC): Fast payments.

Terms in addition to the Public Blockchain

Blockchain

A blockchain is a subset of a distributed database. The Bitcoin inventors originally prototyped the system in 2008. This modern database is made up of separate blocks that are connected together in a chronological chain. Blockchains may be used to store a wide range of data types. It has mostly been utilized as a public ledger for bitcoin transactions to date. A peer-to-peer network comprised of independent nodes uses a consensus process to ensure the blockchain's security and legitimacy. Each node in the network keeps a public and immutable copy of the data.

2 Factor Authentication (2FA)

2 Factor Authentication is a security measure with two layers. It is used by the majority of cryptocurrency exchanges. To log in, you must provide not only a password, but also a code obtained, for example, from the Google authenticator.

Airdrop

An airdrop is a method of distributing coins. End users can typically obtain coins for free or in exchange for doing a small task, such as subscribing to a newsletter, sending a tweet, or inviting others via a personal affiliate link. Cryptocurrency airdrops — the act of depositing cryptocurrency into public crypto wallets — are utilized as a marketing, liquidity creation, and network bootstrapping technique for many different types of blockchain initiatives.

Altcoin

Altcoin - "alternative coin" - is any kind of digital currency other than Bitcoin. Since the launch of Bitcoin, the world's first digital currency, many altcoins (as well as supporting blockchains) have been created. Altcoin digital currencies share many similarities to Bitcoin, but consistently and have significant differences. There are about 20,000 altcoins, and this number is expected to grow significantly in the coming years. Altcoins often develop Bitcoin features. Ethereum, currently the most widely used blockchain, supports digital contracts and separate applications where Bitcoin does not. Altcoins are also often created to cater to the needs of different users. The Litecoin blockchain, for example, can process payments quarterly for the duration of Bitcoin.

Cold Storage

Cold storage is the way to store cryptocurrency offline. The word refers to the use of offline wallets that are not connected to the internet. Cold storage is the most secure way to keep cryptocurrencies since an offline currency becomes less likely to be hacked and stolen. Paper wallets, printed renditions of private keys, and offline hardware and software wallets are all examples of cold storage.