This article examines the intriguing physical properties of nanowires, with particular emphasis on self-organizing atom chains. It begins with an overview of the one-dimensional free electron model and some interesting phenomena of one-dimensional electron systems. It derives an expression for the 1D density of states, which exhibits a singularity at the bottom of the band and extends the free-electron model, taking into consideration a weak periodic potential that is induced by the lattice. It also describes the electrostatic interactions between the electrons and goes on to discuss two interesting features of 1D systems: the quantization of conductance and Peierls instability. Finally, the article presents the experimental results of a nearly ideal one-dimensional system, namely self-organizing platinum atom chains on a Ge(001) surface, focusing on their formation, quantum confinement between the Pt chains and the occurrence of a Peierls transition within the chains.