Search Engine Optimization and Directories

Search Engines and directories are the most important places to get your site for good quality traffic. Many people have concept that search engines and directories are same things. But there is a huge difference between both of them. The only thing that is similar between then is that both show the list of websites you are interested in.
What is difference between search engines and directories?
Search Engines scans the whole internet and makes an index of all the files and when a user searches for any keyword it shows the results that match with the pages in its index. Whereas, [...]