information Retrieval(IR)
Information Retrieval (IR) is finding material (usually documents) of an unstructured nature (usually text) that satisfies an information need from within large collections (usually stored on computers)
“Document” is the generic term for an information holder (book, chapter, article, webpage, etc)
Web Search is the branch of IR where the collection of documents are those located on the web.网页搜索是其中一种应用
IR Systems
Web Search
爬虫
