This type of software testing is very informal and unstructured and can be performed by any stakeholder with no reference to any test case or test design documents. The person performing Ad-hoc testing has a good understanding of the domain and workflows of the application to try to find defects and break the software.
Wolfram Alpha is a computational search engine (sometimes referred to as an answer engine). The interface looks similar to that of a regular search engine but queries typed into the search box result answers to specific questions rather than listings of websites that may be relevant to the query.
Search Engine. A search engine is a web site that collects and organizes content from all over the internet. Those wishing to locate something would enter a query about what they'd like to find and the engine provides links to content that matches what they want. Google.com has become the most widely used search engine on the Internet.