What are the differences between employer and employee associtions?

What are the differences between employer and employee associtions?
Associations are groups that form to represent similar or like interests.

Unions are an example of employee associations. They represent or support the employee.

Chamber of Commerce is an employer association, they represent or support the needs of the employer.

There are many times when employee and employer associations agree on issues and work together, just as there are times when they work against each other.