Cyber security and cyber attacks in information technologies

Cyber security is a concept whose importance is increasing day by day in our lives. With the increase in technological products and the expansion of their usage areas, cyber attacks are also increasing and thus cyber security is gaining importance day by day. Looking at the historical development of cyber security, it is seen that technology has started to be used in almost every aspect of life with the increase in the speed of people's access to technological devices. This situation prevents the cyber security issue from being revealed with all its lines. Today, it is seen that information technologies are actively used especially in sectors that provide services in all areas we can think of such as health, tourism, education, transportation, communication, banking. This situation has forced the sectors to take measures against cyber-attacks and to keep their security policies up to date. Today, cyber-attacks have expanded their sphere of influence. In this period, cyber-attacks, which had a narrow impact such as individual information theft or the seizure of a technological device, have been replaced by a level that threatens the security of countries, and some of these threats have reached a level that may result in the death of people. In particular, it is seen that attacks on the critical infrastructures of countries cause the attacked countries to be cut off from the outside world and to suffer material and moral damages. The aim of this thesis is to put forward what cyber security is and the impact areas of cyber attacks together with the developments in the historical development of technology.