A translation memory is a database that stores "segments", which can be sentences, headings, titles, elements of a list… which have been previously translated.
Translation memories are typically used along with a dedicated Computer Assisted Translation (CAT) tool (technology tool which automates the translation process) a word processing program, and other types of software.
If you own past translation memories in your computer database, you can import them on Wordbee but you can also create new ones. It works as follow: if you have chosen a translation memory to help you in the translation of a new document, whenever a segment, a sentence or even a word that has to be translated is stored in your translation memory, the latter suggests a 100% translation match (or an approximate one if the sentence is similar to a previous one but has one or two words that have changed) , saving time for the human translator who can choose or not to use this match.
Translation memories should not be confused with machine translation. The translation memories are composed of translated sentences stored by the computer whereas the machine translation is the translation of a sentence or of a part of a text by the computer itself. A machine translation system attempts to replace a translator, whereas a translation memory system supports and assists the translator with the translation process.