Information and computer security are closely linked to the IT sector, but they are becoming an increasingly important aspect in daily life since technology is improving and more and more information is stored in information systems and this information is exchanged through various communication channels. Users are often unaware of the potential threats they are surrounded by, resulting in security vulnerabilities and data misuse. The harm caused by cybercrime is great and it is important to react in a timely manner so that no major financial and data losses are involved. Computers and the Internet are now a part of everyday life so it is needed to be aware of possible threats, to monitor trends, and secure yourself appropriately. Ethical hacking is one way that seeks to educate and increase user security. In addition to the concept of Ethical hacking, it is important to educate users about computer threats through various campaigns and projects based on computer security and security on the Internet. Vulnerability detection eliminates system security flaws and increases information security of users. Throughout this paper, types of hacking and hacking attacks will be described. Ethical hackers will be primarily described and what tools and skills are needed for ethical hacking, also we will argue on information security, security vulnerabilities and ways to seek for vulnerabilities. In the end we will be introduced to the concept of penetration testing and compare some of the tools for pentest.