What Exactly Is Bitcoin?
You’ve probably heard the word “Bitcoin,” but what is it really?
This page explains the basic structure and characteristics of Bitcoin in a clear and beginner-friendly way.
Don’t worry if this is your first time learning about it—
you can also explore more detailed explanations in the “Bitcoin Beginner Guide Series” at the bottom of the page.
What Is Bitcoin?
Bitcoin is a revolutionary digital currency (cryptocurrency) known as a decentralized currency, meaning it has no central administrator.
Unlike traditional currencies issued and controlled by governments or central banks, Bitcoin operates on a peer-to-peer (P2P) network maintained by users all around the world.
Bitcoin first appeared in 2009, when a person—or group—using the name Satoshi Nakamoto published a research paper on cryptography.
From that paper came the world’s first mined Bitcoin and the outline of a system for digital payments that requires no central authority and no trusted third party.
Today, Bitcoin can be traded online and has gained attention from individuals and businesses worldwide.
It is especially valued in regions without access to banking services or where local currencies are unstable, serving as a tool for preserving wealth.
What Are the Key Features of Bitcoin?
Bitcoin possesses several characteristics that set it apart from traditional fiat currencies.
These are also the reasons it has gained recognition as a new type of asset.
One of the biggest features is its peer-to-peer (P2P) structure, which eliminates the need for intermediaries like banks.
This allows for faster, low-cost transfers and enables anyone in the world to send and receive value directly over the network.
Another major feature is Bitcoin’s fixed supply limit.
Only 21 million BTC will ever exist.
This prevents the kind of unlimited money printing seen in traditional monetary systems and significantly reduces inflation risk.
The built-in scarcity is one of the reasons Bitcoin’s value continues to rise.
Additionally, Bitcoin operates on a technology called blockchain, which records all transaction history in a fully transparent and tamper-resistant way.
Because the data is distributed across the entire network and not stored in one place, no single user or entity can alter past records—resulting in extremely high security and reliability.
With these combined features, Bitcoin has become a globally recognized trustworthy and highly flexible digital asset.
Why Is Bitcoin Drawing So Much Attention?
Bitcoin attracts global interest for two main reasons:
its dramatic price increases and its unique characteristics compared to traditional assets.
Bitcoin has risen tremendously as a digital asset.
From being worth only a few hundred yen, its price has now exceeded 10 million yen per BTC, creating many so-called “crypto millionaires.”
Another key reason for its popularity is that Bitcoin is not tied to the policies of any nation or central bank.
This independence makes it potentially resistant to currency inflation and financial instability—an appealing trait for people living in countries with weak currencies or for investors seeking diversification.
Some countries have gone even further.
El Salvador, for example, adopted Bitcoin as legal tender.
Bitcoin is seen as a tool to reduce international remittance fees and protect savings from volatile national currencies, and similar movements may spread to other countries.
Thus, Bitcoin is more than just an investment asset—it is being recognized as a new form of money, a long-term store of value, and a global payment method.
Why Do So Many People Lose Their Bitcoin?
Despite being a groundbreaking digital currency, Bitcoin comes with a surprisingly high risk of loss, mainly due to its unique method of asset management.
The central reason is the private key.
Bitcoin is stored in a digital wallet, and access to that wallet requires a private key—a unique code known only to the owner.
A private key functions like a password, but with one crucial difference:
If you lose it, there is no recovery method.
You cannot request a reissue, reset, or assistance from a bank or service provider.
As a result, enormous amounts of Bitcoin—worth millions or even billions of yen—have become permanently inaccessible around the world due to the loss of private keys.
Owning Bitcoin requires strict self-management.
“You must protect your own assets”—this new financial principle is empowering but also imposes a great responsibility on users.
Bitcoin provides freedom as a decentralized currency, but with that freedom comes the risk:
Lose the private key, and the asset disappears forever.