Record Management
Whenever you open your bank account statement, you can see all the transaction or activity perform by you will be only adding to them. In case for any wrong entry, Current Banking system will added a record to update the previous mistake however their internal storage have option to update and delete the same entry which is not used by the bank. This problem is resolve by the Blockchain, which only allow timestamp and merkle tree (complete history of all the previous information) with new change so it is safe and smart ways to solve the banking system problem faced by them.
Decentralized (peer to peer) System
Currently, the entire bank store their information in a single repository, which for any reason get lost then they will have problem to serve their customer however, multiple backup are done as preventive measures to resolve this issue. Cryptocurrency store the information with all the account holder however as you know, information is store in crypto way (human unreadable way as junk values), all the information is confidential even everyone has the information in their laptop with the help of Peer to Peer Technology.
Mining
When you go to bank and give your Bank Cheque(check) then teller will check whether issuer account have appropriate amount is present in their account and if check whether you are correct person who was eligible to receive that amount this activity is done in Cryptocurrency by Miner. In simple language, Whenever you are buying the cryptocurrency then this miner will validate the seller and perform algorithm to check for any fraud or duplicate entry then added your entry in Blockchain after performing complex algorithm and broadcast this information to all the other miner as well as normal user to update their ledger.
Security
All the transaction in crypto world are executed with hash (junk fix values) values, which safeguard your information been disclose to anyone. Nowadays, All the exchanges are requesting for KYC, which will help in validating your information and authenticate whether you have no bad mindset.
Image Reference from the source
https://doubler.zone/1/Miningn.php/