Please describe what each code is doing below:

1. a) Select e.last_name as "Employee", d.department_name as "Department"

From employees e Join departments d

On (e.department_id = d.department_id)

Where e.last_name like 'H%' or e.last_name like 'K%'

b) Select e.last_name, d.department_id, d.department_name

From employees e

Left Outer Join departments d

On (e.department_id = d.department_id);

c) Select e.last_name, d.department_id, d.department_name

From employees e

Right Outer Join departments d

On (e.department_id = d.department_id);

d) Select e.last_name, d.department_id, d.department_name

From employees e

Full Outer Join departments d

On (e.department_id = d.department_id);

e) Select Max (salary)

From employees;

f) Select Max (hire_date)

From employees;

g) Select Min (hire_date)

From employees;

h) Select Sum (salary)

From employees

Where department_id =90;

i) Select Round(AVG(salary),2)

From employees

Where department_id =90;