The subject-matter of this course is the formal expression of  computational models. We shall explore the various models for giving expression to computing processes. The relationship between computing, language and machines, in the context of problem-solving, will be explained with examples. Specifically, we it will be demonstrated that the formalisation and language rendering of computing processes is central to efficient problem-solving. It will also be demonstrated that the ultimate aim of  computing  activities is to give expression to the universe of precises process and system description through the language of symbols.