Computer-aided translation (CAT), similar to the CAD (computer aided design), it actually plays a role of aiding translation, referred to as CAT. It can help the translator complete the translation work with high quality, efficiency and ease. It is different from the previous MT softwares. It does not rely on automatic translation of computers, but completes the whole translation process with the participation of people. Compared to human translation, the quality is the same or better, and the translation efficiency can be increased more than doubled. CAT makes heavy manual translation process automated, and the translation efficiency and quality are significantly improved.

In the process of translation, there are a large number of duplicated or similar sentences and fragments. By Manual translation even the simplest sentences, also need writing again. CAT technology has the mechanisms of auto memory and search; it can automatically store the translated contents of users. When a user translates a sentence, the system automatically searches the sentences the user has translated. If the current translating sentence has been translated by the user, the previous translation results will be automatically given; for similar sentences, translation references and suggestions will be given.

The core of CAT technology is translation memory technology. When translating, CAT is busy building linguistic databases in the background. This is known as translation memory. Each time the same or similar phrase appears, the system will automatically prompt the user to use the closest translation in the memory database. Depending on their own needs, users can use, abandon or edit the repeated text.