The pros of the blockchain include the fact that it provides an immutable record of transactions that can never be altered, an unhackable infrastructure where all transactions are time-stamped and verified, and a virtually unlimited list of potential applications. Many transactions between people or computers can be made more securely with the use of a blockchain. In addition, with cryptocurrencies, you can use the blockchain to send funds across international borders for less than a penny and, depending on the blockchain you use, in seconds. Blockchains also come with some cons. In the context of cryptocurrency, if someone were to steal the code that identifies your wallet, they can send funds anywhere they want. Also, some blockchains require immense amounts of energy to function because of the energy used by the computers that solve the mathematical puzzles that power the chain.

Blockchain is a distributed database formed by a constantly growing list of records or transactions called blocks. The concept of a secure chain of blocks first appeared in 1991, but it wasn’t until a white paper describing its implementation was published under the pseudonym Satoshi Nakamoto in 2008 — and the appearance of bitcoin in 2009 — that it became a reality. While primarily being used to securely track and verify transactions involving cryptocurrency, it has potential for other applications due to its secure nature. Blockchain technology began to be used for more than just monetary transactions in 2014, and it has been applied to such uses as monitoring supply chains, data sharing, digital voting, real estate, and more.

First, learn the basics, such as blockchain concepts, terminology, architecture, and development tools. You’ll also need a working knowledge of cryptography and the blockchain ecosystem. After learning the basics, get familiar with how it's implemented in the real world. Many new blockchain developers like to start with purchasing and storing cryptocurrency. Next, try taking a course to learn coding for blockchain development. Solidity is the recommended platform, but you can also learn other open-source platforms. You’ll need to be able to create a block, make a blockchain, understand and implement a genesis block, add blocks to the chain and validate it, and perform test runs. Finally, you’ll need to learn Smart Contracts and how they relate to blockchain transactions.

Solidity is a programming language intended specifically for designing Smart Contracts and implementing them in blockchain transactions. It’s largely influenced by C++, JavaScript, and Python. You can also use it to develop decentralized apps (dApps) on the Ethereum blockchain. Because it is a language developed primarily for blockchain technology, it provides simplicity and flexibility to blockchain developers. Its importance for blockchain developers is that besides being used to build and deploy smart contracts, they can use it to create contracts for blind auctions, crowdfunding, multi-signature wallets, and voting.

Yes, blockchain is remarkably secure for several reasons. The first being that it cuts out the middleman, making the transaction private. Also, all transactions are verified as valid by multiple nodes called miners in the case of cryptocurrency blockchains. Although some still point to human verifiers as a source of security vulnerability, bitcoin miners have to verify the validity of their own work by a two-step process. First, they need to generate a unique fingerprint for their work on a specific block by solving a difficult numerical problem or some other test providing proof of work. Secondly, each block on the chain is subject to a “consensus protocol,” meaning that all the nodes networked for that piece of blockchain would have to agree that it is valid and not compromised. This requires not only vast amounts of work and computing power, but it needs to be done quicker than others if the miner wants to get paid.