The first step in becoming a proficient Internet researcher is understanding the different search tools. Basically, search tools fall into one of two general categories, indexes and directories. In addition, multi-threaded search tools combine the functions of indexes and directories. If you think of the Internet as a gigantic book, web indexes perform the same function as a book's index, referencing names, technical terms, and concepts found therein. Keep in mind, however, that the book is so big and is growing so fast that no index can keep up.
Indexes offer the most comprehensive compilation of web documents.
Searching indexes tends to return extensive lists of resources, and the task of sorting through them can be overwhelming. Indexes require you to develop expertise in mastering search language. One of the biggest problems with indexes is narrowing your search sufficiently to retrieve a manageable number of documents relevant to your topic. To stay with the book analogy, web directories are like a table of contents, which helps you locate major sections and subsections of a book. In their simplest form, web directories are merely catalogs of links to other web sites.