This document provides an overview of the history and methods of text summarization. It discusses how Hans Peter Luhn introduced the concept of automatic text summarization in the 1950s. There are two main types of summarization: extractive, which selects important sentences from the original text, and abstractive, which understands the context and creates a new summary. The document also presents a case study analyzing word frequency differences between the first 80 and last 40 chapters of the classic Chinese novel A Dream of the Red Chamber.