What is Blockchain Technology? A Step-by-Step Guide For Beginners
The blockchain is an undeniably ingenious invention – the brainchild of a person or group of people known by the pseudonym, Satoshi Nakamoto. But since then, it has evolved into something greater, and the main question every single person is asking is: What is Blockchain?
Is Blockchain Technology the New Internet?
By allowing digital information to be distributed but not copied, blockchain technology created the backbone of a new type of internet. Originally devised for the digital currency, Bitcoin blockchain, (Buy Bitcoin) the tech community has now found other potential uses for the technology.
In this guide, we are going to explain to you what the blockchain technology is, and what its properties are what make it so unique. So, we hope you enjoy this, What Is Blockchain Guide. And if you already know what blockchain is and want to become a blockchain developer please check out our in-depth blockchain tutorial and create your very first blockchain.
A blockchain is, in the simplest of terms, a time-stamped series of immutable records of data that is managed by a cluster of computers not owned by any single entity. Each of these blocks of data (i.e. block) is secured and bound to each other using cryptographic principles (i.e. chain).
So, what is so special about it and why are we saying that it has industry-disrupting capabilities?
The blockchain network has no central authority — it is the very definition of a democratized system. Since it is a shared and immutable ledger, the information in it is open for anyone and everyone to see. Hence, anything that is built on the blockchain is by its very nature transparent and everyone involved is accountable for their actions.
What exactly is Blockchain?
A blockchain carries no transaction cost.
(An infrastructure cost yes, but no transaction cost.) The blockchain is a simple yet ingenious way of passing information from A to B in a fully automated and safe manner. One party to a transaction initiates the process by creating a block. This block is verified by thousands, perhaps millions of computers distributed around the net. The verified block is added to a chain, which is stored across the net, creating not just a unique record, but a unique record with a unique history. Falsifying a single record would mean falsifying the entire chain in millions of instances. That is virtually impossible. Bitcoin uses this model for monetary transactions, but it can be deployed in many other ways.
How Does a Blockchain Work?
Picture a spreadsheet that is duplicated thousands of times across a network of computers. Then imagine that this network is designed to regularly update this spreadsheet and you have a basic understanding of the blockchain. Information held on a blockchain exists as a shared — and continually reconciled — database. This is a way of using the network that has obvious benefits. The blockchain database isn’t stored in any single location, meaning the records it keeps are truly public and easily verifiable. No centralized version of this information exists for a hacker to corrupt. Hosted by millions of computers simultaneously, its data is accessible to anyone on the internet.
To go in deeper with the Google spreadsheet analogy, I would like you to read this piece from a blockchain specialist.
“The traditional way of sharing documents with collaboration is to send a Microsoft Word document to another recipient and ask them to make revisions to it. The problem with that scenario is that you need to wait until receiving a return copy before you can see or make other changes because you are locked out of editing it until the other person is done with it. That’s how databases work today. Two owners can’t be messing with the same record at once. That’s how banks maintain money balances and transfers; they briefly lock access (or decrease the balance) while they make a transfer, then update the other side, then re-open access (or update again). With Google Docs (or Google Sheets), both parties have access to the same document at the same time, and the single version of that document is always visible to both of them. It is like a shared ledger, but it is a shared document. The distributed part comes into play when sharing involves a number of people.
Imagine the number of legal documents that should be used that way. Instead of passing them to each other, losing track of versions, and not being in sync with the other version, why can’t *all* business documents become shared instead of transferred back and forth? So many types of legal contracts would be ideal for that kind of workflow. You don’t need a blockchain to share documents, but the shared documents analogy is a powerful one.” – William Mougayar, Venture advisor, 4x entrepreneur, marketer, strategist, and blockchain specialist
The reason why the blockchain has gained so much admiration is that:
It is not owned by a single entity, hence it is decentralized
The data is cryptographically stored inside
The blockchain is immutable, so no one can tamper with the data that is inside the blockchain
The blockchain is transparent so one can track the data if they want to
The Three Pillars of Blockchain Technology
The three main properties of Blockchain Technology which have helped it gain widespread acclaim are as follows:
Pillar #1: Decentralization
Before Bitcoin and BitTorrent came along, we were more used to centralized services. The idea is very simple. You have a centralized entity that stored all the data and you’d have to interact solely with this entity to get whatever information you required. Another example of a centralized system is the banks. They store all your money, and the only way that you can pay someone is by going through the bank.
The traditional client-server model is a perfect example of this:
When you google search for something, you send a query to the server who then gets back at you with the relevant information. That is a simple client-server.
Now, centralized systems have treated us well for many years, however, they have several vulnerabilities.
Firstly, because they are centralized, all the data is stored in one spot. This makes them easy target spots for potential hackers.
If the centralized system were to go through a software upgrade, it would halt the entire system
What if the centralized entity somehow shuts down for whatever reason? That way nobody will be able to access the information that it possesses
Worst case scenario, what if this entity gets corrupted and malicious? If that happens then all the data that is inside the blockchain will be compromised.
So, what happens if we just take this centralized entity away?
In a decentralized system, the information is not stored by one single entity. In fact, everyone in the network owns the information.
In a decentralized network, if you wanted to interact with your friend then you can do so directly without going through a third party. That was the main ideology behind Bitcoins. You and only you alone are in charge of your money. You can send your money to anyone you want without having to go through a bank.
Pillar #2: Transparency
One of the most interesting and misunderstood concepts in blockchain is “Transparency.” Some people say that blockchain gives you privacy while some say that it is transparent. Why do you think that happens?
Speaking purely from the point of view of cryptocurrency, if you know the public address of one of these big companies, you can simply pop it in an explorer and look at all the transactions that they have engaged in. This forces them to be honest, something that they have never had to deal with before.
However, that’s not the best use-case. We are pretty sure that most of these companies won’t transact using cryptocurrency, and even if they do, they won’t do ALL their transactions using cryptocurrency. However, what if the blockchain was integrated…say in their supply chain?
You can see why something like this can be very helpful for the finance industry right?
Pillar #3: Immutability
Immutability, in the context of the blockchain, means that once something has been entered into the blockchain, it cannot be tampered with.
Can you imagine how valuable this will be for financial institutes?
Imagine how many embezzlement cases can be nipped in the bud if people know that they can’t “work the books” and fiddle around with company accounts.
The reason why the blockchain gets this property is that of the cryptographic hash function.
In simple terms, hashing means taking an input string of any length and giving out an output of a fixed length. In the context of cryptocurrencies like bitcoin, the transactions are taken as input and run through a hashing algorithm (Bitcoin uses SHA-256) which gives an output of a fixed length.
Let’s see how the hashing process works. We are going to put in certain inputs. For this exercise, we are going to use the SHA-256 (Secure Hashing Algorithm 256).
As you can see, in the case of SHA-256, no matter how big or small your input is, the output will always have a fixed 256-bits length. This becomes critical when you are dealing with a huge amount of data and transactions. So basically, instead of remembering the input data which could be huge, you can just remember the hash and keep track.
A cryptographic hash function is a special class of hash functions that has various properties making it ideal for cryptography. There are certain properties that a cryptographic hash function needs to have in order to be considered secure. You can read about those in detail in our guide on hashing.