Different than searching online, a "full-text search" refers to a search that is performed within a Word document or on your local computer. Instead of searching by keyword, as with many online search engines, a FTS compares its results word for word.
In some cases full-text searching can refer to online searching performed by most Web search engines on the Web pages that have been found and added to their caches. All the words on the Web pages are searched, and then indexed, and the user's search request is cross-checked via the indexes.
NetLingo Classification: Technical Terms