This is the 374th most frequent German word.
gleichzeitig
At the same time.
Here, 'gleichzeitig' describes the simultaneous occurrence of two actions: writing and listening.
Sie können sowohl schreiben als auch gleichzeitig zuhören.
They can both write and listen simultaneously.
'Gleichzeitig' indicates that the events occur during the same time window.
Die beiden Veranstaltungen finden gleichzeitig statt.
The two events take place at the same time.
In this case, 'gleichzeitig' is used to talk about performing several tasks at once.