Using vast amounts of computing power, often manifested in private server farms owned by mining collectives that comprise dozens of individuals, miners use highly technical methods to verify the completeness, accuracy, and security of currencies’ blockchains.
Once they have a key, they can obtain and spend cryptocurrency. Without the key, the holder can’t spend or convert their cryptocurrency — rendering their holdings worthless unless and until the key is recovered.

For those who invest in crypto for the long-term using a buy-and-hold strategy, swings like this are to be expected. The recent dips are nothing to be overly worried about, according to Humphrey Yang, the personal finance expert behind Humphrey Talks, who says he avoids checking his own investments during volatile market dips.
Card issuers, networks and manufacturers are working to shrink their carbon footprint as consumers become more environmentally conscious and global carbon emissions climb. Mastercard CEO pushes back against regulatory zeal