Information is the most valuable asset and the most important power of our time, thus it fosters the desire of malicious people to access information through non-legal means. Advanced Persistent Threat (APT) has emerged as a result of this desire. This cyber-attack method became widespread over time and started to be used as a means of financial motivated attack which was initially used by governments. APTs are silent and effective attacks and the damage they make to institutions, organizations and people is great. In this study, APTs are defined and their properties are briefed. The methods and techniques that can be used during these attacks are explained by drawing a life model. The measures that could be taken have been presented by examining the works conducted to prevent this attack. Therefore It is aimed to increase the awareness of the people.