While reading an article I got a word called Keyword stemming. Can anyone please tell me what is it?
It is the process of reducing each word to its stem. E.g. "searched", "searches", "searching" all become just the root word (or stem) "search" in a search index.
In terms of websites, this is frequently used for search functionality. I.e. enabling any form of the search term to find all variations of the supplied keyword. It can significantly improve the search experience.
On top of whats already been mentioned in other answers and assuming you are speaking from an SEO point of view, I'd recommend doing some research on LSI (Latent Semantic indexing) which should be put under the same roof as Stemming.
Some good factual information can be found here : http://hanifsipai.com/latent-semantic-indexing-search-engines-optimimization-seo/
Stemming is the process of removing affixes, suffixes, and pluralizations from words until you have the most basic form of the word. This helps a machine identify words that are similar, eg a keyword and a word in a document. A commonly used stemming algorithm is the Porter Stemmer. It uses a sequence of steps to successively remove keyword modifications.
For example, the word "survives" would be stemmed in the first step of the algorithm to "survive." It would be stemmed further in the fifth step to the most basic form, "surviv." Here is a keyword stemming demo.
The keyword stemming is the process of finding the same keyword in different forms, which leads to the possibility of making maximum hits from the search engine. There is a suffix of the keyword, a prefix that does not have much trouble finding Google. This technique helps to identify similar keywords like - one keyword is the market. it's similar is marketing, marketer.