Machine translation (MT) and Computer-assisted translation (CAT) are two separate but related concepts.
People have long dreamed of fast, accurate, and affordable translations. With the advancement of computer technology in the modern age, people believe that this dream would be fulfilled with machine translation. However, the quality of machine translation leaves much to be desired even to this day. The translation of many texts (such as this one) still relies on the work of an expert human translator.
Consequently, people still wish to improve the efficiency and reduce the cost of human translations. In the 1970s, computer engineers began developing computer-assisted translation (CAT) tools to help improve the speed and accuracy of human translators.
From the above, we know that:
Source texts are completed translated by machines, with no humans involved throughout the process. Since humans are not part of the translation process, the accuracy of the translated text is often subpar and require human post-editing.
Source texts are translated by humans, who are aided by functions that can improve the speed and accuracy of the translation in the process. The most well-known function for improving the efficiency of the translation process is the translation memory (TM).