Finn and Ellie sell oranges at a produce stand. Finn earns $5 for each crate of oranges he sells. At the end of the week, Ellie has earned $20 more than Finn. The following expression shows Ellie's earnings:

20 + 5z

In the expression, what does the second term represent?

Finn's earnings at the end of the week
The number of crates of oranges Ellie sold
Ellie's earnings at the end of the week
The number of crates of oranges Finn sold