SEO stands for Search Engine Optimization. Before going ahead what do you mean by Search Engine? So, basically, search engine is an application which solves user’s query. Whatever you search on Search Engines, it gives you right answer. So, Google is a search engine also Yahoo, Bing are few example of search engine.
Search Engine Optimization is a technique to optimize our website on search engines. We have to rank our website on Google/ yahoo/ Bing by increasing quality of our website.
But exactly how search engine works?
There are three main functions in search engine;
So, crawler or spider is an application who traverse on whole Internet and collect the data. Whatever information you put on your website crawler crawls (or fetch or collect) it. After fetching the information it will store that information in database. After that it will sort that all information. When user searches particular query, crawler find the answer from database and shows the relevant answers, this process is called as Indexing.
Sandbox is an imaginary space in which crawler puts under-constructed websites or blocked websites. So, if you want to rank your website on Google, of course on 1st position so, you need to do SEO. And it is totally free of cost.
If you want to know about how to implement seo than click on: On-Page Basic Factors and On-Page Advance Factors.