#1
Glimpse is an index and query system that allow for search through a file system or document collection efficient. Glimpse is the default search engine in a large information retrieve system. It has also been use as part of some web search engine.

#2
The main process in an information retrieve system are document index, query process, query evaluation and relevance feedback. Efficient update of the index is critical in large document collection. Query process may involve query expansion.

#3
The retrieve model in a search engine determine a document relevance to a query. An example of a retrieve model is the vector space model in which document and query are represent as vector. Vector operation are use to determine similar between query and document. Often, cosine similar is use as the main vector operation.

#4
Cluster is the task of group similar object. In information retrieve, cluster can be use to find document with similar content or to group together term that appear frequent together in document.

#5
Cluster are create from short snippet of web document retrieve by web search engine. These cluster can be use to group similar document for more efficient browse of search result.