When a segment is approved during translation and there are other identical segments in the source text, MateCat will ask you whether the translation should be propagated to all those segments or only to the current one. If you choose the first option, MateCat will automatically populate all the target segments having the same source throughout the project with your translation.
They will be labelled as Autopropagated as you can see in the example below:
The same translation will appear for all identical source segments and their status will be Translated. You will not need to approve them manually by clicking on the Translated button.