Crypto glossary
Pseudonymity
Pseudonymity means users act through addresses rather than names, but every transaction is public and traceable, so identities can be uncovered.
A Bitcoin or Ethereum address is a pseudonym: it does not carry a name, yet everything it does is recorded permanently on a public ledger. Anyone can see its balance, who it paid and who paid it. That is very different from anonymity, where actions cannot be linked to a persistent identity at all.
The gap between the two is where blockchain analytics firms operate. By clustering addresses that are spent together, matching deposits to exchanges that collect identity documents and tracking patterns over time, investigators regularly link addresses to real people. Law enforcement has used this to trace ransom payments, darknet markets and stolen funds.
For ordinary users, pseudonymity means that publishing one address, for example on social media or an invoice, can expose their whole financial history linked to it. Privacy tools such as CoinJoin, fresh addresses for each payment and privacy-focused coins reduce linkage but do not guarantee anonymity, and some attract regulatory scrutiny.
Example
A freelancer shares one Ethereum address to get paid; a client looks it up on a block explorer and sees the freelancer's other income, savings and NFT purchases.