Wide AreaInformationServer (WAIS) is the oldest information search program on the Internet and is based on full- text analysis of databases. It is particularly well suited for searching document content.
WAIS searches the information sources word by word for the occurrence of certain keywords specified as search criteria and displays the relevant documents on the results pages( SERP). Before WAIS begins a text search, it must select from a long list of information sources those that are to serve as the data basis for the subsequent full-text analysis. These are usually large databases or collections of documents on specific topics. After selecting the databases, the keywords can be entered and the search can begin.