Difference between Search Engine and Subject Directory

1. Search Engine:
A search engine, as the name suggests, is defined as an application designed to carry out web searches and enables users to locate information on WWW. Search engines are machine-driven and are used to find resources such as web pages, Usenet forums, videos, etc., assigned to individual words.

Examples: Yahoo search, ASN, Live search, Google search, etc.

2. Subject Directory:
Subject Directory, as the name suggests, is defined as a collection of websites that include organized browsable subject categories and subcategories. Directories are human-driven and therefore can deliver higher quality content. They are considered best for browsing and searching of more general nature and may include a search engine for searching their database.

Examples: Yahoo directory, Open directory, Google directory, etc.

Difference between Search Engine and Subject Directory:

S. No.	Parameters	Search Engine	Subject Directory
1.	Basics	It is an online tool that is used to locate or search for information on WWW.	It is an online database of websites and online information set up by subject and category.
2.	Maintained and reviewed	It is generally maintained and reviewed by computer robotics.	It is created, maintained, and reviewed by human editors or experts.
3.	Allows users	It allows users to find or locate information on the internet using phrases and keywords.	It allows users to find or locate information on the internet using hierarchy.
4.	Search and Display	It locates and displays relevant information based on formulas and algorithms using an automated software program.	Directories are organized by human beings who discover new websites and relevant information by exploring the internet themselves and by reviewing submitted websites.
5.	Usage	They are used mainly for research, shopping, and entertainment.	They are used mainly to search broad topics, current events, organization or business homepages, etc.
6.	Size	They are bigger than directories as it includes billions of web pages.	They tend to be smaller than search engine databases.
7.	Application	It is considered good to look for specific or complex information and its advanced features allow to refine the search and improve results.	It is considered best if one wants to browse broad topics and it can give a good idea about the amount and type of web-based information on the topic.
8.	Searching by user	User search content or information on database of search engine.	User search only websites included and identified by directory.
9.	Indexing of website	In order to index a Website, search engines automatically collect information about it.	Directories demand that a Website submission be listed in the directory.
10.	Listing	A search engine automatically lists regardless of content quality. Search engines employ specific algorithms to filter and deliver the most relevant and valuable information to users.	To assure quality, websites must meet certain requirements before being featured in a directory,
11.	Fees	Search engines do not charge a fee to publishers.	Some directories charge a fee for listing in their directory.