Dewey Decimal Classification, the Library's shelving system
The Library’s main book collection is sorted and shelved according to the Dewey Decimal Classification System, DDC. The system was created by the American librarian Melvil Dewey (1851–1931). According to DDC, books are grouped by subject with a numerical code for each subject area.
This is what it looks like when you have found a book in the library search service:
The Book Collection is the main part of the library's books which is placed on open shelves, where you pick up the book you want yourself. In the library search service, the Call No shows you which shelf/section to go to. Within each call number section, books are sorted alphabetically by author’s last name or the first word in the book title, which is shown after the Call Number.