Scopus is published by Elsevier. Scopus' website advertises that it is the largest abstract and citation database of peer reviewed literature and quality web-sources.
It includes abstracts from around 17,000 publications and has 40 million records with some going back as far as 1823. Covering the life sciences, physical sciences, health sciences, social sciences & humanities.
More than half of Scopus' content is from Europe, Latin America and the Asia Pacific Region giving it a broad international focus.
Scopus has a channel on YouTube with a number of videos that can assist you with using the database.