meaning of (crunch the paper together in a ball)

[learning_english]

you take a piece of paper, hold it in the palm of your hand, and then make a fist. You crunch the paper together in a ball. When you unfold the paper, we would describe it as "crinkly." Just like the wrinkled flesh of a very old person, or the edges of lasagne noodles. Something that isn't smooth and has very fine lines and wrinkles.

Please explain the highlighted group of bold words. [particularly the meaning of `crunch' and `ball' in this context]
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Please let me know if I have made any mistakes in any of my sentences.

[Conchita]

'You crunch the paper together in a ball' means:

You make a ball by crumpling up (= folding) the piece of paper.

Crunch = crush (something crisp).

Ball = round object, especially for playing games.