Solidity, Blockchain, and Smart Contract Course (Article # 01)

 Solidity, Blockchain, and Smart Contract Course

Hi... everybody and welcome to the free Digital Lancing blockchain and solidity beginner to expert full course python

Solidity, Blockchain, and Smart Contract Course

blockchain in smart contract world is a very collaborative community so if you have questions some of the best places that you can go going to stack overflow and tagging your question with the specific technologies that you're working on make an issue on the github repo that we're working with go to stack exchange eth and make a question there as well jump into the discord of the technology that you're working with or even on github discussions if those are there learning to become a blockchain and solidity engineer is actually a lot more than just learning solidity becoming comfortable with all the tools in the space is going to be just as essential as becoming familiar with solidity itself and continuing the conversation on maybe twitter or reddit or any of these other channels and maybe even showing your stuff in the next ethereum or chainlink hackathon are going to be majorly beneficial to increasing your skill as an engineer now before we get actually coding a lot of people want to understand what is actually happening with all this blockchain stuff what is blockchain what is a smart contract how did this all get started and understanding these core fundamentals will actually shape the way you code and architect your smart contract applications so learning these is really really critical. however if you're already familiar with blockchain and you just want to jump into the solidity feel free to grab a timestamp from the description and jump to that section now since you're here though you've probably heard of bitcoin before bitcoin was one of the first protocols to use this revolutionary technology called blockchain. 

the bitcoin whitepaper was released by the pseudo-anonymous satoshi nakamoto and it outlined how bitcoin could be used to make peer-to-peer transactions in a decentralized network.

this network is powered by cryptography and allows people to engage in censorship resistant finance in a decentralized manner due to some of the features of bitcoin a lot of people took it to be as a superior store of value over another asset like let's say gold and that's why it's commonly referred to as digital gold similar to gold. there is a scarce and set amount of it on the planet and people use it to buy and sell similar to other assets you can read more about the original vision in the white paper now this was a fantastic breakthrough and in a little bit we're actually going to look through how blockchains can actually work and how all of this is possible but some people took this and saw this technology and thought that they could do even more a few years later a man named metallic buterin released a white paper describing a new protocol called ethereum which used this same blockchain infrastructure but with an additional feature and in 2015 they released this project called ethereum him and a number of other co-founders took this blockchain technology. and applied it in ways that people can make entirely decentralized applications decentralize organizations and build smart contracts and engage in agreements without a third-party intermediary or centralized governing. 

Force their idea was to take the same pieces that made bitcoin great and add smart contracts to it and in fact this technically wasn't even a new idea back in 1994 a man named nick zabo proposed a technology called smart contracts a smart contract is a self-executing set of instructions that is executed without a third party intermediary they come to life on a blockchain and these smart contracts are really going to be the core thing that we're going to be working with and we're going to be developing smart contracts are similar to regular traditional contracts that people make between each other but instead of writing these contracts down on pen and paper or typing that on the computer it's entirely written in code the terms of the agreement are written in code and automatically executed by the decentralized blockchain network instead of being written pen and paper and executed by the two parties or three parties or however many parties involved this is one of the main differentiators between the ethereum protocol and the bitcoin protocol now technically bitcoin does also have smart contracts however.

they're not touring complete meaning that they don't have the full range of capabilities as a turing complete application like ethereum this is actually an intentional move by the bitcoin developers they view the bitcoin network as an asset whereas ethereum and the ethereum and developers viewed that acid as an asset and also a utility for people to build these smart contracts now these smart contracts are revolutionary technologies and we're going to talk a little bit more about what their advantage is in a little bit but they actually come with a fatal flaw with what's known as the oracle problem these blockchains are deterministic systems and we'll learn why they're deterministic very soon and this determinism means that they're a walled garden meaning that everything that happens in these smart contracts and on this blockchain happens in this little box now of course if you want these smart contracts to actually be these digital superior agreements then they need some way to interact with the real world and get real data and external outside the blockchain computation this is where oracles come into play oracles are devices that bring data into a blockchain or execute some type of external computation so great so oracles are the solution now blockchains can talk to the real world right well not quite our blockchains and smart contracts are these decentralized applications and in order for them to stay decentralized that means they would also need to get their data and external computation from a decentralized manner as well your on-chain logic will be decentralized on the blockchain but you'll also need your off-chain data and external computation decentralized as well combining these on-chain logic settlement layers and these off-chain data and external computation builds what's called hybrid smart contracts.

A large majority of d5 applications in the largest applications today are these hybrid smart contracts this is where the protocol chain link comes into play chain link is a decentralized modular oracle network. that allows you to bring data into your smart contracts and do external

computation and it's these hybrid smart contracts that can have this on-chain settlement and interact with the real world in some meaningful way chain link is an incredibly powerful oracle network because it allows us to get data get randomness do some type of upkeep or really customize our smart contracts in any way we want and elevate them to do anything that we want them to do now throughout the course when we're talking about smart contracts oftentimes...