Ethical hacking can be defined as the hacking of computers done with permission. Hacking can be defined as the process of finding vulnerabilities in a computer system to gain unauthorized access and perform malicious activities. These activities range from deleting system files to stealing sensitive information. However, hackers are often hired by renowned software companies to hack into their system/servers to find vulnerabilities and weak endpoints so that they can be fixed. This practice is followed by almost every software company to take precautionary measure against legitimate hackers who have malicious intent. Such people, who hack into a system with permission, without any malicious intent, are known as ethical hackers and the process is known as ethical hacking.
One must keep in mind that hacking of any system without permission is illegal and can lead to extreme consequences if you are caught in the act. There are provisions of years of imprisonment to people found guilty of unethical hacking or any other cyber-crime.