This review discusses the electronic and transport properties of carbon nanotubes, focusing on theoretical aspects and their relation to experimental results. It begins by introducing the concept of one-dimensional (1D) systems and their significance in condensed matter physics. The review then explores the structure of carbon nanotubes, emphasizing their unique properties as either metallic or semiconducting, depending on their diameter and chirality. The electronic properties of carbon nanotubes are analyzed using various models, including the tight-binding model and zone-folding approximation, which help explain the band structure and density of states. The review also addresses the effects of curvature, tube-tube interactions, and topological defects on the electronic properties of nanotubes. Transport properties of carbon nanotubes are discussed, covering conduction regimes, transport length scales, and the influence of disorder on transport. The review highlights the role of quantum interference effects, such as weak and strong localization, and the impact of inelastic scattering mechanisms, including electron-phonon interactions. It also addresses the effects of Coulomb blockade, Luttinger liquid behavior, charge density waves, and superconducting transitions in nanotubes. The review concludes by emphasizing the importance of nanotubes in both fundamental and technological applications, and the ongoing efforts to understand and control their properties through experimental and theoretical studies.This review discusses the electronic and transport properties of carbon nanotubes, focusing on theoretical aspects and their relation to experimental results. It begins by introducing the concept of one-dimensional (1D) systems and their significance in condensed matter physics. The review then explores the structure of carbon nanotubes, emphasizing their unique properties as either metallic or semiconducting, depending on their diameter and chirality. The electronic properties of carbon nanotubes are analyzed using various models, including the tight-binding model and zone-folding approximation, which help explain the band structure and density of states. The review also addresses the effects of curvature, tube-tube interactions, and topological defects on the electronic properties of nanotubes. Transport properties of carbon nanotubes are discussed, covering conduction regimes, transport length scales, and the influence of disorder on transport. The review highlights the role of quantum interference effects, such as weak and strong localization, and the impact of inelastic scattering mechanisms, including electron-phonon interactions. It also addresses the effects of Coulomb blockade, Luttinger liquid behavior, charge density waves, and superconducting transitions in nanotubes. The review concludes by emphasizing the importance of nanotubes in both fundamental and technological applications, and the ongoing efforts to understand and control their properties through experimental and theoretical studies.