The process of searching involves four stages:
- Crawling
- Indexing
- Algorithms
- Ranking
1. Crawling
Search to answer a query starts with “crawling” into different websites for relevant information. The search engine scans the site to acquire data such as – the page title, images, keywords of the content etc. An automated “bot” visits each page of the web, access the content and other information provided there. Modern crawlers consider the page layout, placement of advertisements on the website where the links are provided etc.
2. Indexing
The processing of all the data driven from crawling and organizing them in the database is called as Indexing. Example: Imagine a room full of DVDs of movies. Going through each DVD to know about the movie means crawling and writing the list of names of movies. This process is same as Indexing.
3. Algorithms
Algorithms are special programs and formulas that look for clues to better understand the search query.
4. Ranking
The Ranking Process is the last stage of the searching process. When a search query is entered, based on the clues provided by algorithms, the relevant documents are pulled out from the index and most relevant results are displayed to the users. The order of display is called ranking.