Five students have the first names Clark, Donald, Jack, Robin and Steve, and have the last names (in a different order) Clarkson, Donaldson, Jackson, Robinson and Stevenson. It is known that Clark is $1$ year older than Clarkson, Donald is $2$ years older than Donaldson, Jack is $3$ years older than Jackson, Robin is $4$ years older than Robinson. Who is older, Steve or Stevenson and what is the difference in their ages?
1. Let's denote the ages of the students by \(a_1, a_2, a_3, a_4, a_5\) corresponding to Clark, Donald, Jack, Robin, and Steve respectively.
2. Similarly, denote the ages of the students by \(b_1, b_2, b_3, b_4, b_5\) corresponding to Clarkson, Donaldson, Jackson, Robinson, and Stevenson respectively.
3. According to the problem, we have the following relationships:
   \[
   \begin{align*}
   a_1 &= b_1 + 1 \quad \text{(Clark is 1 year older than Clarkson)} \\
   a_2 &= b_2 + 2 \quad \text{(Donald is 2 years older than Donaldson)} \\
   a_3 &= b_3 + 3 \quad \text{(Jack is 3 years older than Jackson)} \\
   a_4 &= b_4 + 4 \quad \text{(Robin is 4 years older than Robinson)}
   \end{align*}
   \]
4. We need to determine the relationship between \(a_5\) (Steve) and \(b_5\) (Stevenson).
5. Since the first names and last names are permutations of each other, the sum of the ages must be equal:
   \[
   a_1 + a_2 + a_3 + a_4 + a_5 = b_1 + b_2 + b_3 + b_4 + b_5
   \]
6. Substitute the given relationships into the equation:
   \[
   (b_1 + 1) + (b_2 + 2) + (b_3 + 3) + (b_4 + 4) + a_5 = b_1 + b_2 + b_3 + b_4 + b_5
   \]
7. Simplify the equation:
   \[
   b_1 + b_2 + b_3 + b_4 + 10 + a_5 = b_1 + b_2 + b_3 + b_4 + b_5
   \]
8. Cancel out the common terms on both sides:
   \[
   10 + a_5 = b_5
   \]
9. Rearrange to find the relationship between \(a_5\) and \(b_5\):
   \[
   b_5 = a_5 + 10
   \]
10. This means Stevenson is 10 years older than Steve.

The final answer is \( \boxed{Stevenson \text{ is 10 years older than Steve}} \)