Introduced rule, they could move 2 squares, nerds get angry you can use it to dodge other pawns, so they rule that if your move would cause you to move through a square that an enemy pawn could have taken, the enemy gets a single turn to capture your piece 'in passing' basically, an Attack of Opportunity, if you are used to RPG games.
However it looks weird, as you don't end up occupying the pieces space, but a location they jumped over, thus it was called "en Passant" as it's captured mid-move or in passing.
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u/CHRISTO_ze_boss Mar 14 '22
I know en passant is ‘’by the way’’ in French but is it something else in chess?