I know that Enron and WorldCom were corporation scandals and that some people lost a lot of money, but how it is directly related to accounting?

Sarbanes-Oxley... PCAOB...

It's created a new regulatory environment for auditors that helps ensure that financial reporting information is honest and accurate.

For accountants, it means a lot more work - new internal controls, more intense audits of process and procedures - all intended to validate financial information, and in turn protect investors and the public interest.

They used creative accounting tricks to hide losses thereby showing positive results for the shareholders and the stock price