Introduction: The use of computers, tablets, smartphones (PC) and the internet is currently a common daily activity of the majority of people in developed countries. That's why the question is, what impact does it have on our lives? In cases where frequent use of computers, and in particular the internet, causes people problems in life, some authors use terms such as internet or computer addiction. In the professional community, however, there is no agreement in terms of terminology in this area, and there is discussion as to whether such behavior is a separate mental disorder or is the manifestation of another mental disorder. Aims: The goal of the study was not to solve this problem, but to collect actual data on how much time teens spend using computers and the internet and what activities they are doing during this time. Research sample and methods: We administered a simple questionnaire to a group of 1558 primary and secondary school students. The average age of participants was 15.7 years, with 53 % of the sample being male. Results: All participants used PC and Internet for study or entertainment purposes. PC and the Internet were used an average of 5 hours a day, and two-thirds of this time, participants used it for fun. The time spent with a PC and internet for fun differed in individual activities. The majority of the time was spent on social networks, the least by watching pornography and online shopping. We also found that women in research sample spent more time on computer and on internet than men, and they also differ in time spent on selected activities. Conclusion: Our results suggest that what is more important than time spent on PC and internet is what activities the adolescents spend during this time.

Key words: computer – internet – addiction – adolescent