Annotation This diploma thesis deals with a communication used within information technologies, especially within computer slang. The theoretical part of this work is dedicated to the term `slang{\crq} and its position within the structure of the national language. It presents different definitions of slang and the opinions of linguists on defining this term. Diploma thesis also describes the linguistic and non-linguistic aspects of slang. The second part of the work sets out commentary on the history of information technologies and it also introduces an overview of the written sources concerning the computer slang. The intention of this work was above all to set a dictionary of the computer slang mostly composed on a basis of questionnaire research which was done throughout the period 2007 {--} 2009. The linguistic material was subjected to analysis; it is focused on basic characteristics of slang, especially on the synonymy and expressivity. It also explores the computer anglicisms and character of their adaptation in the Czech language.