Foundations · 05 / 86 · 3 min
Nodes, clients, and forks
A node is a computer keeping the history. A client is the software it runs. A fork is a disagreement about the rules.
A website is someone else's report. A fork is a fight about the rules, not a gift of coins.
A worked case
An exchange credits coins from a fork and calls it free money. To claim the other side yourself, a person reuses a signature. The signature spends coins on the chain they still care about. The fork was a rule change. The loss was the signature.
Your view of the chain
If you only look through an exchange or a website, you are trusting their view. A node you run is you checking the history yourself. Most people will not run one. Knowing that you are not is already useful.
Forks
A soft change can stay compatible. A hard fork splits the rules. Coins can exist on both sides for a moment. The name often stays with whichever crowd, companies, and exchanges follow.
A fork is not free money. Claiming coins on a copy of the chain can expose your keys if you sign the wrong thing.
1 August 2017, two bitcoins
A node is a computer that checks the rules for itself. A client is the software it runs. Almost everyone looking at a price is looking at a company's client, or at a website in front of that. If you have never run a node, you are trusting their view of the history. That can be a reasonable choice. It is still a choice, and it is not the same as checking.
A fork is what happens when clients disagree about the rules and both sides keep going. On 1 August 2017 bitcoin split. One side kept the existing rules. The other raised the size of a block and called itself Bitcoin Cash. For a moment, keys that held bitcoin held a claim on both chains. Exchanges decided which one they would credit, and when. People who tried to claim the new coins by importing keys into a strange wallet sometimes signed something they did not understand. A fork is a rule change with a marketing department. It is not a dividend.
The practical test is whose software you believe. If the only place a balance exists is an exchange's database, you are not reading a node. You are reading a firm.
Read it yourself
These links are the record. They are not a recommendation, and they are not instructions. A news story or a court paper can still be wrong about a detail. The check does not change because a famous name is in the story.
Apply the check
Open a question. The line is about this topic. It is not a verdict that anything is safe.
Exchanges that choose which side of a fork to list.
The client version the majority runs.
Whoever you trust for the view, if you do not check a node.
Check yourself
Is the exchange's balance the same as checking the chain yourself?
No. It is their report of your account.
After this you can tell a node from a website, and treat a fork as a rule change, not a gift.