The books your library owns are listed in its computer catalog, along with other resources such as videos of films or TV shows, newspapers, or sound recordings. You can search the catalog by author, title, or topic keywords.
The catalog is not the same as an index or database (which you would use to find articles published in journals or magazines). The catalog lists all the books in the library collection, as well as all other separately published materials (films, DVDs, newspapers, magazines). The catalog will tell you whether the library holds a certain issue of a periodical, but it will not tell you what is in that periodical. For that, you need a periodical index or database.