This is the 33rd most frequent German word.
durch
"Through" or "by means of."
In this example, 'durch' indicates movement across or from one side of a location to another.
Er ging durch den Park.
He walked through the park.
In this sentence, 'durch' describes the medium (the window) through which something (the light) passes.
Das Licht scheint durch das Fenster.
The light shines through the window.
Here, 'durch' introduces the means or method by which an action was accomplished.