This paper analyzes the concepts of data and information, it is explained what personal data is and what it includes, and it also describes what the General Data Protection Regulation is because it regulates the collection and processing of personal data. Also, it is explained how data processing was done throughout history because technology has greatly advanced, from engraving signs on stone or bone, to the fact that today speech can be converted into text through digital technologies. With regard to technological development, in everyday life the most common example is leaving personal data via the Internet and social networks, which is recognized and specifically described in this paper. The conducted survey shows that most people are aware that their personal data is collected, especially when they use internet services, social networks and applications. However, they often do not fully understand the scope and purpose of data collection. Also, terms of use and privacy policies are often long and written in complex language, making them difficult for average users to understand, so most people accept the terms of use without reading them, meaning they are unaware of how their data may be used. Every day it becomes easier to invade an individual's privacy because personal data can be found in any place, and therefore it is necessary to look back at the dangers arising from today's technologies. For this reason, the area of personal data protection was regulated for the first time in the Republic of Croatia with the adoption of the Personal Data Protection Act in 2003. Keywords: personal data,