Bitcoin has no exchange rate, because it is an electronic currency and universal, so its exchange rate is the same as other legal tender.
Bitcoin mining and node software is based on P2P network, digital signature and cryptographic evidence to initiate and verify transactions. Nodes broadcast transactions to the network. After these broadcast transactions were verified by miners, miners confirmed them with their own work certificates. Confirmed transactions will be packaged into data blocks, which will be strung together to form a continuous data blockchain.
Each bitcoin node will collect all unconfirmed transactions and collect them into a data block, which will be integrated with the previous data block. The miner node will attach a random adjustment number and calculate the SHA-256 hash operation value of the previous data block. Mining nodes keep trying until they find a random adjustment that makes the generated hash value lower than a specific target.
Because hash operation is irreversible, it is very difficult to find the random adjustment number that meets the requirements, and a trial and error process that can predict the total number is needed. At this time, the workload proof mechanism comes into play. When a node finds a solution that meets the requirements, it can broadcast its results to the whole network. Other nodes can receive this newly solved data block and check whether it conforms to the specification. If other nodes really meet the requirements by calculating the hash value, then the data block is valid, and other nodes will accept the data block and attach it to their existing chain.