The deep Web, hidden Web or invisible Web is normally defined as the content on the World Wide Web that is not accessible by means of a search on standard search engines.
The deep Web is estimated to be at least 500 times larger than the searchable or surface Web.
Content on the deep Web includes:
- Dynamically-changing, updated content, such as news and airline flights
- Content available on sites protected by passwords or other restrictions.
- Special content not presented as Web pages, such as full-text articles and books
- Non-text files
- The content of databases created by programs such as Access, Oracle, SQL Server, and MySQL
- Blog postings
- Discussions and other communication activities on social networking sites, for example, Facebook and Twitter
- Bookmarks and citations stored on social bookmarking sites
There are various means for retrieving this hidden content from the Internet including: structured query processing, data mining techniques, Web crawlers, query interfaces, specialised search engines and tailored search techniques.
Inspec covers the latest research in this area with the following Controlled Index Terms:
- data mining
- database management systems
- information retrieval
- online front-ends
- ontologies (artificial intelligence) SSQl
- query processing
- relational databases
- search engines
- social networking (online)
- user interfaces
and Classification Codes:
- c7210N Information networks
- c7250R Information retrieval techniques
- c7250N Search engines
- c6160 Database management systems
- c6160D Relational databases
- c6180 User interfaces
- c6170K Knowledge engineering techniques