A reader asking "Is bitcoin legal?" is measuring coins against bitcoin, the one most people meet first. Players who pay a casino in crypto often weigh it against USDT or Ethereum, wonder whether bitcoin and cryptocurrency mean the same thing, and ask whether holding it is allowed at all. Each comparison below takes one of those questions, explains what sets the coins apart, and says nothing about where any price is going.
Bitcoin vs USDT is a comparison between two different jobs. Bitcoin has no issuer; new coins come from the network's own rules, and its price is set by buyers and sellers, so it can rise or fall sharply within a day. USDT is a stablecoin issued by a company that aims to keep each token equal to one unit of a traditional currency, backed by reserves it reports holding. Its steadiness rests on trust in that issuer, which can also freeze specific addresses. Neither is better in general; each suits a different need.
Is bitcoin legal? The answer depends on the country, and no single rule applies everywhere. Some countries regulate buying, holding and exchanging it, some restrict how banks or businesses may deal with it, and a few ban it outright or ban key uses of it. Tax rules differ just as widely, and many places treat selling or swapping coins as something to declare. Rules also change over time, and a website that opens in a browser proves nothing about whether using it is permitted. Local rules are the only answer that counts.
Quick answers
What does the value of USDT depend on?
On the reserves its issuer reports holding and on trust in that issuer, which can also freeze specific addresses.
Is selling or exchanging bitcoin taxed?
Tax rules differ by country, and many places treat selling or swapping coins as something to declare.
Why does an Ethereum wallet need ETH?
Every transaction on Ethereum pays gas in ETH, so a wallet holding only tokens cannot move them without some ETH.
Is bitcoin the same as cryptocurrency?
No. Bitcoin is one cryptocurrency, the first and best known, among thousands of coins and tokens.