“World­Cat is a data­base of bib­li­o­graphic infor­ma­tion cre­ated and con­tin­u­ously updated by some 25,000 OCLC mem­ber libraries around the world. World­Cat records describe spe­cific works and con­tain a list­ing of insti­tu­tions that own an item, referred to as “hold­ings.” Insti­tu­tions use hold­ings infor­ma­tion to cre­ate local cat­a­logs, arrange inter­li­brary loans and con­duct ref­er­ence work.”

“World­Cat was cre­ated in 1971 so that libraries could share cat­a­loging infor­ma­tion from a cen­tral data­base, increas­ing work­flow effi­ciency and the abil­ity to locate and loan mate­ri­als. It took the OCLC coop­er­a­tive almost 34 years, from August 26, 1971 to August 11, 2005, to add 1 bil­lion hold­ings in World­Cat. It has taken just seven years and eight months to add the next billion.” 

“World­Cat spans six mil­len­nia of recorded knowl­edge, from about 4800 B.C. to the present. It encom­passes records for books, seri­als, sound record­ings, musi­cal scores, maps, visual mate­ri­als, mixed mate­ri­als and com­puter files.”

From OCLC Mem­ber Update [oclc@oclc.org]

“Find more about World­Cat on the OCLC web­site, and watch World­Cat grow as libraries around the world con­tribute to the database.”

(Hold­ings con­sti­tute a higher num­ber than titles.  A(nother) hold­ing is counted for each library that owns a title.