Pawn goes sideways without taking a piece?

In this game: nb.lichess.org/3npsCIB4#22
Black's move #11 - the plack pawn is moving sideways without taking a piece...

Since im a newbie - maybe someone can explain this for me?

(and also white pawn at C4 disappears?)
Must be a bug? Or a rule I dont know?

OK....
Google is of course my friend...

En passant was the answer... :-)

But new rules for me.

probably a hacker, i saw one too, he moved a pawn to the last rank and the pawn became a queen, pretty website but too many hackers

lol

Well - i see.
Stupid question...
But we were all new once - weren't we?

(and @alex_beneath - to be honest - maybe even not the best way to welcome newbies?)

@gastronauten #7
Don't worry about it. It happens to all of us.
When I was young and just learned the rules I joined a chess-club. In one of my first games the same thing happened and I thought the guy was trying to cheat me.
I really wanted to hit him! Badly. :-)

ps. Alex's post was a funny one. Don't take it too serious.

I agree fully with #9, dont worry you will soon learn the interesting and fascinating game, the rule of en passant which took place in your game is that if a pawn moves 2 squares and you have a pawn besides it then on the NEXT move you have the choice of capturing the pawn diagonally forward, this might sound a bit confusing at first but you will soon get used to it!