How does immutable work?

Could you please elaborate on how immutable works in the context of cryptocurrency and finance? I'm particularly interested in understanding the mechanisms behind its operation and how it ensures the integrity of transactions within the blockchain. Does it involve any specific technological advancements, and how does it differ from traditional financial systems? Also, could you provide some examples or scenarios where the immutability of data has been particularly beneficial in the field of finance? Thank you for your insights.