It means that access to resources is free and unrestricted, without legal or technical restrictions.

Benefits of open publishing:

•  Greater dissemination and global reach of projects and resources
•  Generates greater accessibility to resources
•  Facilitates cooperation and the free sharing of knowledge
•  Allows for the adaptation, reuse, and improvement of resources.

Examples:

•  Scientific articles: Publications available at no cost.
•  Software: Programs that can be downloaded and used freely.
•  Data: Datasets accessible for analysis and studies.