Non-small cell lung cancer (NSCLC) is the major type of lung cancer, accounting for 85%. The common options for treatment include surgery, radiotherapy, chemotherapy, immunotherapy, and molecularly targeted therapy depending on the stage, histology, genetic changes, and health condition of patients. Sadly, just 15% of individuals with stage III NSCLC are still alive after five years, which indicates a bad outlook. Because of the use of PD-1 and CTLA-4 immune checkpoint inhibitors (ICIs), immunotherapy has unquestionably made the most progress in the field of NSCLC. This article offers a comprehensive exploration of NSCLC, encompassing its epidemiological characteristics, pathological processes of different classification, and the diverse treatment modalities available. It emphasizes the pivotal role of immunotherapy, particularly immune checkpoint inhibitors (ICIs) for treatment some classification of patients. The article discusses challenges and prospects, such as identifying patient populations that benefit most from immunotherapy and addressing issues like immune-related adverse events (irAEs) and immune resistance. Through this analysis, the article underscores the significant strides made in NSCLC treatment and the ongoing efforts to improve patient outcomes.