Natural Language Processing (NLP) is a central research area in artificial intelligence and provides the foundation for modern Large Language Models (LLMs). This 20-hour introductory course will mainly cover the following three aspects: (1) fundamental concepts and traditional techniques in NLP; (2) recent advances leading to and enabled by LLMs; and (3) selected advanced developments and applications in multimodal settings, where language is combined with other data modalities such as vision and audio.