What is Latent Semantic Analysis (LSI Indexing) ?

Search engines usually will check for the frequency of keywords and their presence number of times to check relevancy. But in this method, accuracy is very less.

For Example, search results will be able to distinguish words with similar meanings but some words with multiple meanings will fail to differentiate. So Search Engines uses LSI(Latent Semantic Indexing) to understand keywords in the context of words on entire web page.