Step 1: Analyze continuity.
The function \( f(x) = |x| - 1 \) is continuous everywhere because both \( |x| \) and constant shifts are continuous functions.
Step 2: Analyze differentiability.
The function \( f(x) \) is not differentiable at \( x = 0 \), since the left-hand and right-hand derivatives are not equal there.