The field of oncology is revolutionized by immunotherapy. immunotherapy is a fundamental breakthrough in cancer treatment that focuses on boosting the natural defense for malignant cell elimination. Cancer immunotherapy is of different forms including, virus therapies, adoptive cell transfer, cytokine therapies, immune checkpoint inhibitors, and cancer vaccines, all of which have promise future developments and clinical applications. To maintain homeostasis several pathways of immune signaling are employed that inhibit or stimulate immune responses. These immune signaling pathways help to keep immune responses maintained by avoiding autoimmunity and chronic inflammation, these immune signals that regulate immune responses in the body are also known as immune checkpoints. The responses of numerous self-regulating checkpoints of the immune system are exploited by the cancerous cells. Immune checkpoint inhibitors and monoclonal antibodies (mAbs) are becoming the most important immunotherapies, despite the progress of Acceptance and Commitment Therapy (ACT). ICIs are the antibodies that inhibit the receptors of the immune checkpoint, PD-1/PD-L1, and CTLA-4. It has potential benefits in cancer treatment for long-term survival and antitumor effect production in malignancies of a broad spectrum.