This master's thesis analyses the impact of digital resources and tools on translation quality in computer-aided translation (CAT). Thesis presents the most important definitions from the mentioned area, and quality is analysed through the quality assurance process (QA). The quality is checked on bilingual english-croatian texts, obtained by alignment of corpus of texts written in those languages. Several CAT tools are used in different tasks: alignment, terminology extraction and analyse of translation quality. Their comparison will show how much the translation quality increases by using all the features they offer.