Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE departments ( department_id VARCHAR )
TABLE: CREATE TABLE employees ( department_id VARCHAR )

### Question ###
display the department name and number of employees in each of the department.

### Accurate SQL ###

SELECT department_name, COUNT(*) FROM employees AS T1 JOIN departments AS T2 ON T1.department_id = T2.department_id GROUP BY department_name