tf-idf

TF-IDF stands for Term Frequency-Inverse Document Frequency. It's a way to measure how important a word is to a document in a collection of documents. It's used to identify meaningful words in text-based information like webpages or documents.

To understand it, think of a library. It has lots of books. In each book, there are lots of pages with different words. We can measure how important a word is in each book by counting how often it appears on each page. This is called "term frequency," because it shows how often a term appears in a document.

But the same word might also appear in lots of other books in the library. If a word is very common, it might not be very meaningful in a particular book. To measure how important a word is in one book compared to all the other books in the library, we use "inverse document frequency." In other words, if a word is rare, it's probably more important to the book it appears in, compared to books where it's very common.

So, when we use TF-IDF, we're measuring how important each word is to a document compared to all the other documents in a collection. This helps us identify meaningful words in text-based information.