Dismissal or firing is generally thought to be the fault of the employee, whereas a layoff is generally done for business reasons (for instance a business slowdown or an economic downturn) outside the employee's performance.
Australian Unions. In Australia, a union is sometimes referred to as a trade union or a labour union. A union is an organisation of workers or employees who have joined together to achieve common goals. These goals can include seeking higher pay and better working conditions, fighting for job security and protecting the integrity of a trade.
A union is workers joining together to pursue policies and goals beneficial to one and all. Nothing more, nothing less. In other words, a union is you and your fellow workers, acting in concert to better your everyday working conditions. A union is what gives the individual worker a voice in decisions and events that directly affect him or her in an undertaking that constitutes a major portion of life, that is, work.