Lemmatization is a natural language processing technique that reduces words to their base or root form, known as a "lemma." Unlike stemming, which simply cuts off prefixes or suffixes, lemmatization considers the context and meaning of the word. For example, the words "running" and "ran" are both reduced to the lemma "run." This process is essential for improving the accuracy of text analysis and search algorithms. By converting words to their base forms, lemmatization helps in grouping similar words together, making it easier for computers to understand and process human language effectively.