Help me understand where I went wrong

I don't get this game, I was doing well, then when I move d5 my chance to win plummets... why? And then every move after the machine hates what I am doing

I am obviously aware of the blunder at the end, but its the positional play I'm trying to understand.

Likewise, Stockfish on this game says that c5 is a HUGE blunder, massive loss to the game, but I didn't even see why? Is the engine just working on a whole other level of analysis that my brain can't possibly understand?

You lose your rock -.-

Dude ...

@myocarditis c5 drops the rook on e8. The bishop is attacking it.
No, its not working on a level you cant understand. It just takes practice. With time, positional play and tactical play become easy and almost intuitive.

What is wrong with losing the rook to improve the position?

@myocarditis Oh ok.
Let me explain. It has long been understood that rooks are significantly better than other pieces, like bishops or knights. THis is because in an endgame with equal numbers of pawns, if one side has a rook and the other has a knight, the side with the rook nearly always wins.
For this reason, a point system has been introduced. I dont know how long ago it was invented, but it gives the pieces the following values.
Pawn - 1 point
Knight and Bishop - 3.5 Points
Rook - 5 Points
Queen - 9 Points
As you can see, allowing a knight or bishop to take your rook is a serious loss of points! Rooks are just better pieces than bishops and knights.
NOTE: Sometimes this is not true. The position can have an effect.
Basically, you should not give up a rook unless you are improving your position a LOT by doing so. c5 is not enough improvement to justify the loss of the rook.

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