When a material is deformed (stretched, squashed, bent) it can be deformed in 3 possible ways.
1: ELASTIC deformation
(it's deformed but then snaps back when released)
2: PLASTIC deformation
(it's deformed and stays deformed when released)
3: BROKEN
(it breaks!)
Ceramics just break.
Metals and Polymers can usually do all 3.
But not always, for example:
elastic band - 1 or 3
fuse wire - 2 or 3
cast iron - just 3