encyclopedia

encyclopedia
a book or set of books giving information on many subjects or on many aspects of one subject and typically arranged alphabetically.
　
computer
an electronic device for storing and processing data, typically in binary form, according to instructions given to it in a variable program.

Google
Google is an American multinational corporation specializing in Internet-related services and products. 
These include online advertising technologies, search, cloud computing, and software.
 Most of its profits are derived from AdWords.

Twitter
Twitter is an online social networking service that enables users to send and read short 140-character messages called "tweets".
 Registered users can read and post tweets, but unregistered users can only read them.