A database is an organized collection of records. The collected records can be in any format such as printed, electronic, visual, audio, statistical, or combinations
A database can be as simple as name entires in an address book or as complex as a databank that provides information related to a subject discipline in a combination of formats.
Generally there are two types of databases: free and fee. Google Scholar and PubMed are examples of free databases. The information is open for everyone to access free of charge. Fee databases, however, charge you to search their records for the information comes from commercial publishers and are packaged by commercial database vendors. Most of the library databases are fee-based. Fortunately, libraries pay for access to these databases and make them freely available to our students, faculty and staff.
Thanks to Peter Cohn at MIT Library for granting permission to adapt his guide.