Been stuck on step 9 in python, building an employee generator. I don't understand what is meant by concatenate.first_name = 'John'
last_name = 'Doe'
full_name = first_name + ' ' + last_name
address = '123 Main Street'
address += ', Apartment 4B'
employee_age = 28
employee_info = full_name + " " + first_name + " " + last_name + " " + employee_age