This document presents an overview of text mining. It discusses how text mining differs from data mining in that it involves natural language processing of unstructured or semi-structured text data rather than structured numeric data. The key steps of text mining include pre-processing text, applying techniques like summarization, classification, clustering and information extraction, and analyzing the results. Some common applications of text mining are market trend analysis and filtering of spam emails. While text mining allows extraction of information from diverse sources, it requires initial learning systems and suitable programs for knowledge discovery.