# What is the geometric significance of differentiable vs continuously differentiable?

What is the geometric significance of differentiable vs continuously differentiable for functions (based on $$\mathbb{R}$$)? By 'geometric' i mean the appearance of the plot of such functions.

Perhaps this question is best splilt into three categories: $$\mathbb{R}$$ to $$\mathbb{R}^n$$, $$\mathbb{R}^n$$ to $$\mathbb{R}$$, and $$\mathbb{R}^n$$ to $$\mathbb{R}^m$$.