A collective agreement is an agreement between workers' and employers' organisations. If a collective agreement is required for the company, it gives the right to better terms.
Among other things, to get paid on public holidays, the right to more holiday and holiday pay, more overtime pay and a better pension scheme. With a collective agreement, you also have the right to enter into agreements with the management of the company regarding things that are special to you. The union will help you put in place a collective agreement.