A database is a collection of information which can be searched. Some databases cover a single subject or discipline area, others are multidisciplinary.
Types of information and information sources that are in databases are:
Not all databases are full text. Databases usually have one of three levels of content: index, full-text, or a combination of both.
When people talk about searching the internet they are usually referring to a search engine, like Google, which scans millions of pages.
Databases are developed, structured and maintained to meet specific information needs. They:
For a succinct comparison of database and web search engines go to The University of Auckland. Business Information Skills Online Beyond the web.
The video Library databases vs Search engines below, produced by the Wellington Medical and Health Sciences Library at the University of Otago, describes the differences between searching the web and searching databases.