Today we won't talk about tips for flirting or hooking up.

Today we'll discuss some fundamentals.

What is blockchain?

I remember when I first entered the industry in 2021, I posted a moment on social media saying, “There’s nothing more hip-hop than decentralization in this world.” So I quit dancing and writing, and plunged into this industry that has ruined my life.

Now, four years later, I haven't made much money; in fact, I owe a lot of debt. After seriously reflecting on myself, I realized I had never truly integrated into this industry.

The essence of blockchain is a public ledger without an administrator, where anyone can verify it. Compared to traditional databases, like banks, companies, governments, and enterprises—you can only choose to trust them because they seem to have backing. The core of blockchain is—that you don’t need to trust any one person.

Because no one can unilaterally change the records, and anyone can verify them themselves.

Therefore, in blockchain, anything that appears to be decentralized is actually centralized—like some CEXs—because we all indulge in illusions about this industry.

Blockchain does one thing: bookkeeping.

1. Transactions
A transaction at least contains the following four parts:
from: who pays
to: who receives
amount: how much
and signature: (proof that it's you)

Blockchain doesn’t know who you are; it only knows that this private key authorized the transaction.

2. Block
You can think of a block as a bundle of all transactions over a period of time, similar to a cashier settling all customers at a convenience store at once.

A block contains: multiple transactions, the hash of the previous block, a timestamp, and a nonce.

Each block points to the previous one, so changing one block requires changing all subsequent blocks.

That’s why “immutability” comes from the blockchain structure.

3. Hash
The physical law of blockchain.

Hash functions have the property that: changing the input by even one character produces a completely different output.
They are irreversible and allow quick verification.

Blockchain uses hashes to bind the order of blocks, preventing history from being altered.

The core of a block, as mentioned above—without an administrator or boss—who makes the decisions? The answer is the consensus mechanism.

Consensus mechanism = who has the right to record transactions.
Currently, there are only two types: PoW and PoS.

PoW (Proof of Work) - BTC
PoS (Proof of Stake) - ETH, BNB, SOL

In PoW, the logic is: whoever computes faster gets to record, where computing power equals authority. It is highly secure, resistant to attacks, but consumes a lot of electricity and is slow. That’s why BTC is considered digital gold.

In PoS, the logic is: the more coins you stake, the higher your chances of being chosen. It’s energy-efficient and fast. However, capital tends to be more centralized, so most projects run on PoS.

So if you understand these concepts, you should realize that the essence of blockchain is to make it so you don’t need to trust any one person. If you still trust someone or a project, that might be the reason you and I lose money.