Specialized text share a common feature, that is the repetition of the same fragments. It can be single words, phrases or even the whole sentences. When a repetition happens a natural course of action is to copy the earlier thanslation to a new spot. This can be done manually, but it is better to automatize this process. That is the purpose of the translation assisting programs ie. CAT-s (CAT - computer assisted translation). These tools register the text entered by a translator and connect it with the source text. In this way, a database is created that contains pairs of translation units (usually whole sentences) in two languages. If in the text appear a sentence that was once translated, the program automatically inserts it saving translator's time.
There are many programs such as CAT. They all work more or less according to the principles described above, but of course may differ in detail and offered features. Eg. some programs, such as Wordfast, are called. attachments to the Microsoft Word editor, while other, such as Trados pack, can act as an overlay, but they also offer independent editors (eg. TagEditor). The most popular CAT tools include SDL Trados, Wordfast (free of charge in the past), Déjà Vu and OmegaT (free of charge). Obviously this is not a full list.
Before we start working, it is worth to realize that CAT programs do not make translations by temselves, but only substitute text fragments that had been previously translated by an interpreter. Therefore, we cannot refer to these processes as so-called machine translation, because, in fact, a man performs the translation, and the programs are intended only as a supporting tool, like a word processor or computer dictionary.