ISSN (International Standard Serial Number) is a unique eight-digit identifier that is assigned to serial publications, such as magazines, newspapers, and journals. The ISSN is used to identify and track these types of publications, which are typically issued on a regular basis (e.g. weekly, monthly, quarterly).
The ISSN is issued by the International ISSN Center, which is an international organization that is responsible for assigning and managing ISSNs. Each ISSN is unique to a specific publication, and it is used to identify and distinguish that publication from others. The ISSN is typically included on the masthead or title page of a publication, and it is also used in bibliographic databases to help identify and locate specific publications.
ISSNs are useful for librarians, researchers, and other professionals who need to keep track of and access serial publications. They help to ensure that these publications can be accurately and consistently identified and tracked over time.