About 10 minutes with practice. You only need something to take notes with. No real wallet details or payments are part of this lesson.
Course contents · Lesson 7 of 21
- Bitcoin without jargon · Marked complete
- Keys, custody and keeping control · Marked complete
- Payments for humans, including Lightning · Marked complete
- Money, prices and units · Marked complete
- Follow a payment from request to receipt · Marked complete
- Addresses, networks and QR codes · Marked complete
- Confirmations and patience · Marked complete
- Fees buy scarce block space · Marked complete
- Backups before dependence · Marked complete
- Scams, urgency and trusted routes · Marked complete
- Privacy is a practice · Marked complete
- Custody is a relationship · Marked complete
- Reading a Lightning invoice · Marked complete
- Exchanges and access to bitcoin · Marked complete
- Volatility and practical planning · Marked complete
- A fair invoice for creative work · Marked complete
- Donations with accountable purpose · Marked complete
- Proof of work and honest energy questions · Marked complete
- Bitcoin and Litecoin: related ideas, separate networks · Marked complete
- Read Bitcoin news with a source trail · Marked complete
- Capstone: welcome a newcomer safely · Marked complete
What you will learn
- Distinguish unconfirmed and confirmed transactions.
- Explain why confirmation policies differ.
Blocks are not appointments
An unconfirmed transaction has not yet been included in the accepted chain of the observing node. Inclusion gives it a confirmation; later blocks build additional work above that history. The target interval between Bitcoin blocks is an average, not a timetable. A payment does not become faulty just because a stopwatch passes ten minutes.
Why recipients wait
Competing chain histories and double-spend attempts make a first observation different from a stronger settlement assessment. A recipient chooses a policy appropriate to the value, delivery reversibility and threat they face. There is no universal count that makes every transaction absolutely irreversible. A café, a digital download and a large irreversible delivery can reasonably need different procedures.
Communicate the condition
Suppose a fictional artist’s checkout says “awaiting confirmation.” The useful message tells the buyer that the payment has been seen and what remains before delivery. It should not imply that a second payment is needed. If an explorer and wallet disagree, inspect their network, transaction identifier and synchronization state. Avoid escalating from uncertainty to a rushed resend; first establish which transaction each screen is describing.
Practice on paper
A transaction is included in block 100. The observer’s current tip is block 102 on the same chain. How many confirmations does the transaction have in this example?
Reveal the worked answer
Three: inclusion at 100 counts as one, followed by 101 and 102. This arithmetic does not decide an appropriate acceptance policy or guarantee that no reorganization can occur.
Check your understanding
Choose an answer in your head or on paper, then reveal the explanation. Retry whenever you like. Answers are not submitted or scored; completion marks are your own learning notes.
1. Is the average block interval a delivery guarantee?
- Yes
- No
Reveal answer 1
No. Actual intervals vary.
2. Should every recipient use the same confirmation policy?
- Always
- No, context matters
Reveal answer 2
Context matters. Value, reversibility and operational risks affect the policy.
Take this with you
Waiting for evidence is different from assuming something is broken.
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