Raman spectroscopy and imaging are powerful tools for studying the properties of graphene. This review summarizes recent advances in using Raman spectroscopy and imaging to determine the number of layers in graphene, understand its electronic and physical properties, and investigate its behavior on different substrates. Raman spectroscopy can quickly and unambiguously determine the number of graphene layers, as the 2D band of single-layer graphene (SLG) is sharp and symmetric, while that of multilayer graphene is broader. The G band intensity also increases with the number of layers, allowing for layer determination. The strong Raman signal of SLG compared to graphite is explained by an interference enhancement model. The effects of substrates, top layer deposition, annealing, and folding on graphene's properties are studied. Epitaxial graphene grown on SiC substrates is also examined, revealing strong compressive strain. Raman spectroscopy is effective for determining doping type and concentration. The study highlights the importance of Raman spectroscopy in understanding graphene's properties for potential applications in nano-electronic devices. The results show that Raman spectroscopy is a valuable technique for characterizing graphene and its interactions with substrates. The review also discusses the effects of different substrates on graphene's properties, the impact of defects and strain on its electronic structure, and the unique properties of folded graphene. The study provides insights into the electronic structure of graphene and its potential applications in various fields.Raman spectroscopy and imaging are powerful tools for studying the properties of graphene. This review summarizes recent advances in using Raman spectroscopy and imaging to determine the number of layers in graphene, understand its electronic and physical properties, and investigate its behavior on different substrates. Raman spectroscopy can quickly and unambiguously determine the number of graphene layers, as the 2D band of single-layer graphene (SLG) is sharp and symmetric, while that of multilayer graphene is broader. The G band intensity also increases with the number of layers, allowing for layer determination. The strong Raman signal of SLG compared to graphite is explained by an interference enhancement model. The effects of substrates, top layer deposition, annealing, and folding on graphene's properties are studied. Epitaxial graphene grown on SiC substrates is also examined, revealing strong compressive strain. Raman spectroscopy is effective for determining doping type and concentration. The study highlights the importance of Raman spectroscopy in understanding graphene's properties for potential applications in nano-electronic devices. The results show that Raman spectroscopy is a valuable technique for characterizing graphene and its interactions with substrates. The review also discusses the effects of different substrates on graphene's properties, the impact of defects and strain on its electronic structure, and the unique properties of folded graphene. The study provides insights into the electronic structure of graphene and its potential applications in various fields.