Monocytes and macrophages are essential components of the innate immune system, playing crucial roles in homeostasis, immunity, and disease pathophysiology. They are phenotypically distinct mononuclear phagocytes that differentiate from monocyte/macrophage progenitors in the bone marrow. Monocytes can be classified into classical (Ly6C^hi), intermediate (Ly6C^int), and non-classical (Ly6C^lo) subsets, while macrophages exhibit functional polarization into M1 (pro-inflammatory) and M2 (anti-inflammatory) phenotypes. These subsets respond to environmental cues and tissue microenvironments, modulating inflammatory and homeostatic responses. Inflammation triggers monocyte recruitment to sites of infection or injury, where they differentiate into macrophages that can either promote inflammation or aid in tissue repair. Macrophage polarization is influenced by various factors, including chemokines, integrins, inflammasomes, and metabolic reprogramming. Inflammasomes, such as NLRP3, are involved in the activation of inflammatory cytokines and pyroptosis, contributing to disease pathogenesis. Metabolic reprogramming, including glycolysis, fatty acid oxidation, and TCA cycle modifications, is critical for macrophage function and polarization. Therapeutic interventions targeting macrophages include inhibitors of NLRP3, MIF, and integrins, as well as modulation of metabolic pathways. These approaches aim to reduce inflammation and promote tissue repair in inflammatory diseases. Understanding the biology and regulation of monocytes and macrophages is essential for developing effective therapies for inflammatory conditions.Monocytes and macrophages are essential components of the innate immune system, playing crucial roles in homeostasis, immunity, and disease pathophysiology. They are phenotypically distinct mononuclear phagocytes that differentiate from monocyte/macrophage progenitors in the bone marrow. Monocytes can be classified into classical (Ly6C^hi), intermediate (Ly6C^int), and non-classical (Ly6C^lo) subsets, while macrophages exhibit functional polarization into M1 (pro-inflammatory) and M2 (anti-inflammatory) phenotypes. These subsets respond to environmental cues and tissue microenvironments, modulating inflammatory and homeostatic responses. Inflammation triggers monocyte recruitment to sites of infection or injury, where they differentiate into macrophages that can either promote inflammation or aid in tissue repair. Macrophage polarization is influenced by various factors, including chemokines, integrins, inflammasomes, and metabolic reprogramming. Inflammasomes, such as NLRP3, are involved in the activation of inflammatory cytokines and pyroptosis, contributing to disease pathogenesis. Metabolic reprogramming, including glycolysis, fatty acid oxidation, and TCA cycle modifications, is critical for macrophage function and polarization. Therapeutic interventions targeting macrophages include inhibitors of NLRP3, MIF, and integrins, as well as modulation of metabolic pathways. These approaches aim to reduce inflammation and promote tissue repair in inflammatory diseases. Understanding the biology and regulation of monocytes and macrophages is essential for developing effective therapies for inflammatory conditions.