In some directories i have seen - search here using our search engine.... So r directories same as search engines or a mini search engine? like say - if they crawl pages..index them...
Web Directories don't index pages. Search engines do. Directories are meant to be maintained by editors. Directories exist for internet users and search engines. Search engines bots crawl directories and get information.
I think crawl feature is for search engine, not directory. But there are directory script that have crawl feature if you interested : ADP
so directory is just a collection of websites categorized.....which search engines and users can use.........
It really depends on the directory script. What you describe above is certainly possible, and I have seen variations on that theme attempted. A lot of directories use crawlers at the submit stage, to help with the submission process. And many will also crawl in order to maintain listings and check for broken links. So the line between a directory and a search engine is never absolute. However, what you get with the search function on a directory is usually a search of the listings within it, and the categories, rather than a search of anything that is external to a directory. I have often thought that a search engine that searches only the websites approved in a certain directory could be a very useful thing. But I haven't seen it done yet.
No directory can get close to a search engines. Directories sort only websites, but search engines offer the user, the exact content that he is looking for (at least that's what they are for.) At most, you can call them micro-search engines.
The answer is that a directory contains a mini search engine, or at least that's how I read it. Depending on your definition of a search engine (there are lots) there are a wide variety of engines I plucked this definition out for you as its relevant to directories.