Return statement

I am aware a Return statement can return 2 things, 1. A value to be passed to the calling method and 2. An expression.

However given the below code snippet, im unsure what the Return statement is returning

public List GetCustomers(string sortExpression)

string sql = @"SELECT CustomerId, CompanyName, City, Country, Version
FROM [Customer] ".OrderBy(sortExpression);

return Db.ReadList(sql, Make);

The Return statement is going to another class entirely, I assume this still falls under an Expression rather than a value but to an external class and method?

Thanks