The beginning of the magnetic link is "magnet:? Xt=urn:btih: ",which is a fixed format magnetic link. Among them, "magnet:?" Is the protocol header, indicating that this is a magnetic link; "xt=" indicates the type of link; "urn:btih:" is also a fixed identifier, indicating that the content of the link is calculated and verified by using the hash algorithm based on BT protocol. The following character string is generally a series of 16 numbers and letters calculated by hash algorithm, which are used to identify resources or files and ensure the integrity and correctness of downloading. Because the magnetic link can directly skip the intermediate link and directly download resources at the download client, it is very convenient and popular to use because it does not need to download through the designated download page like the traditional download method.