The term "search engine" is often used to describe both crawler-based search engines and human-powered directories. These two types of search engines gather their listings in radically different ways.
Crawler-Based Search Engines:-Crawler-based search engines, such as Google, create their listings automatically.
If you change your web pages, crawler-based search engines eventually find these changes, and that can affect how you are listed. Page titles, body copy and other elements all play a role.
Human-Powered Directories:-A human-powered directory, such as the Open Directory, depends on humans for its listings. You submit a short description to the directory for your entire site, or editors write one for sites they review.
Changing your web pages has no effect on the listings that u do. Things that are useful for improving a listing with a search engine have nothing to do with improving a listing in a directory. The only exception is that a good site, with good content, might be more likely to get reviewed for free than a poor site.