A collective labor contract, also called workers' collective agreement or collective agreement of all jobs, is a peculiar type of contract entered into between workers and employers of a company or a labor sector. This agreement can regulate all aspects of the employment relationship such as salaries, hours, breaks, vacations, working conditions, union representation, etc. The conditions established by this type of contract are the minimum conditions under which labor relations must be concluded in its scope of application, in such a way that the contract signed by each worker can improve them, but not worsen them.

Collective bargaining is a process by which representatives (unions) and employers negotiate and agree on working conditions, which may include wages, hours, benefits, and other work-related issues.

Collective bargaining allows the parties to negotiate its content, either between the employers themselves and their workers—met in a works committee—or between their associations such as unions and union centers, guilds, employers' associations and professional associations, etc. If this negotiation fails, the various pressure groups that support the parties – which may be the participants themselves or others such as political parties or other associations – may resort to other measures to force the agreement, such as strikes, demonstrations or lockouts.

This type of employment contract applies to all workers in a certain area, such as a company, a sector or a geographical location, although not all of them—or the union to which they are affiliated—have participated directly in collective bargaining or are not affiliated with the signatory unions, although it may depend on the legislation of each country. For this reason, in some systems, collective agreements are similar in their treatment to legal norms of general application, such as laws or other systems.

Furthermore, an agreement cannot contravene the constitution, laws or regulations that prevail in a place, so provisions that violate these legal norms, such as maximum hours or minimum wages, cannot be agreed upon. Therefore, as a source of law, the agreement is subject to the legal system.

In comparative law we find two systems in this regard, depending on whether the general principle is heteronomous regulation or autonomous regulation. In the first case, the legislation provides for the carrying out of various acts, to the fulfillment of which the entry into force of the collective agreement is subject. Such acts may consist of those that seek to publicize it - taking into account its nature as a professional law -, within which it is worth mentioning the deposit, registration and publication, also, those that are aimed at guaranteeing its legality, such as the case of approval by some state agency.[1]​.