Bitcoin blockspace basics

The on-ramp for newcomers and agents: what a block holds, how it is sized, and how its space is priced.

• What is a block
  Blocks, transactions and the chain: what a Bitcoin block holds, how its size is counted, and how many there are.
• Block weight and the limit
  Why a block's capacity is counted in weight units, the 4,000,000 WU consensus limit, and the 400,000 WU limit on a standard transaction.
• Vbytes
  The virtual byte: a quarter of a transaction's weight, the unit fee rates are quoted in, and why it differs from a transaction's raw size.
• Fees and the mempool
  Where a transaction waits before it is mined, how its fee is quoted in sat/vB, and what Blockspace Holdings' own node and fee estimates read.
• The witness discount
  A witness byte weighs a quarter of a base byte, so it costs a quarter as much at the same fee rate. The short version, with links to the full page.
• Halvings and the subsidy
  The block subsidy, what Blockspace Holdings' documents say about it and the halving schedule, the fees beside it, and the sats coinbases never claimed.
• Why blockspace is scarce
  The fixed weight limit is the fact; what limits blockspace underneath it is Blockspace Value Theory's argument, labelled as theory.

Sources #

1. Blockspace Value Theory · block.space/docs/bvt
2. block.space docs: data types · block.space/docs/datatypes