This is carried out by cybersecurity experts that are hired by enterprises to deliberately break through the enterprise systems. They hold specialisation in penetration testing and can identify ways to break through a system. This helps businesses in determining and correcting certain vulnerabilities before actual hackers take advantage of such situations. The fact that this type of hacking by a professional is called ethical is because they are hired by the company to
keep the infrastructure secure.
Some popular tools used by ethical hackers include Acunetix, Burp Suite Pro, John the Ripper, Kismet, Nessus, Wireshark, etc. Irrespective of which tools you are using for ethical hacking, it will always involve a great deal of learning, experimentation, and testing.