What is ethical hacking
Websites and online services consist of large and complex pieces of software, and errors in them are not excluded. Small ones, like output errors instead of the correct page filling, are not a problem. But larger ones can lead to an attacker gaining access to secret information, user accounts, and publishing arrays of data stored on the site.
No matter what efforts the site owners make
It is difficult to create absolute protection for the code, and it happens that important vulnerabilities go unnoticed. For example, a login form that allows endless selection of passwords to log in to an account. Or a more serious problem: command or SQL injection into an interface that does not handle quotation marks in the query string, and the program qualifies them as part of an SQL or system command.
Checking a website or online service for the presence of such vulnerabilities in the security system to improve it is called ethical hacking, or penetration tests. This is a targeted search for errors in the code by an IT specialist who works in the field of security research.