Master's thesis shows the development of OPACs, its features, advantages and disadvantages. COBISS/OPAC is presented in detail. A review of school curricula has shown that information literacy is included in the curricula of schools with the program library and information science (LIS) in which pupils and students become familiar with COBISS/OPAC catalogue. With the help of LIS they should master the information process to independently acquire information and knowledge through information sources. It was found that LIS allows much free rein in the implementation of content, scope and methods, although students are expected to gain a comparable level of IT skills at the end of secondary education. The laxity of LIS leads to variations in learning COBISS/OPAC. With this research we want to examine the differences between grammar and non-grammar school students especially in the learning of COBISS/OPAC segments; databases, search and examination results. The method used for data collection was a questionnaire, which was filled in by librarians and students. The results showed that first-year students have different previous knowledge of COBISS/OPAC. In secondary school there are further differences in learning between different educational programmes. It was found that grammar school students have more information literacy skills and are familiar with more COBISS/OPAC segments. As a result, they have less difficulty in accessing online databases. The survey findings could lead to a systematic programme planning of LIS in order to achieve transparent transmission of information skills in all educational programmes.