Scalability in blockchain refers to how fast a blockchain can process transfers per second and the limits associated with it. If a blockchain has a high capacity, that is, it can process a lot of transfers per second, then it is considered to be a highly scalable.
For example, Ethereum is often criticized for having low transaction capacity. Therefore, it is not a highly scalable blockchain. Nano on the other hand can process 5 times to 10 times the transactions Ethereum can process every second. It is a highly scalable blockchain.
Scalability in blockchain means how many transactions per unit of time the blockchain can process. The scalability of a blockchain is an important prerequisite for its mass adoption. But scalability, security and decentralization present a dilemma where it is hard to get all three. The security of a blockchain simply means protection against false transactions. Decentralization means that no single entity is able to control the blockchain.
Good scalability + good security = poor decentralization
A good example of a payment system like this is credit cards. The transfers are on a centralized ledger 100% controlled by the credit card company. They have excellent scalability. Visa, or example, can process about 1,700 transactions per second. They also have pretty good security against false transactions and if fraudulent transactions happen, they are able to easily roll them back. But what's totally lacking is decentralization. Credit card companies have total control over the ledger and they can easily censor any transactions they choose or are required to by the government.
Good decentralization + good security = poor scalability
Bitcoin is the poster boy of this variant. Bitcoin is very secure against false transactions. The combined hashing power of the network is enormous and changing the ledger to insert a false transaction would require taking over 51% of the network which would be prohibitively expensive. Bitcoin is also pretty decentralized (at least in theory) and this censorship resistant. But Bitcoin's scalability is very poor. The blockchain can only process about seven transactions per second at a high energy and financial cost.
Good scalability + good decentralization = poor security
A blockchain like this has a high maximum throughput of transactions and no single central entity is capable of censoring transactions. However, because not much is done verify transactions, it is relatively easy to inject false transactions into the chain.
Blockchain scalability, namely: Since blockchain technology was discovered and gave birth to bitcoin as the world's first cryptocurrency, this technology has a capacity of 1 MB per block sizenya with the ability to confirm 7 transactions per second. With the development of bitcoin that is increasingly being used by people, the more the number of transactions per second, the more slow the transaction (transfer time).
If in this second instance there are 100 transactions, then the blockchain only processes 7 transactions in the first second, then 97 other transactions wait in the next second alias queue. Similar to the quota of pilgrims. So what happens is the expansion of the network or also known as HARDFORK / SEGWIT which gives birth to new types of coins such as:
With a completely new system and amount of supply. But this does not add to the ability to confirm the coin master transaction, namely bitcoin.
To handle several government projects such as elections, railways etc. it's true that blockchain technology is very useful, but not for payment technology.
Blockchain scalability is a serious problem in the blockchain field, because when this problem can be solved quickly, it can deliver blockchain to wider users. Various solutions are offered by developers and many community nodes, such as lightning network, sharding and others.
Scalability It is important to increase transaction capacity on blockchain, and increase the number of decentralized applications (Decentralized App / DAppp),