Nanowires are ultrafine wires or linear arrays of dots,formed by self-assembly. They can be made from wide range of materials. Semiconductor Nanowires made of (silicon, indium phosphide and gallium nitride), insulating Nanowires (sio2,tio2), Molecular Nanowires  either (organic e.g. DNA) or inorganic  Mo₆S_9−xI_x ), Metallic Nanowires (Ni, Pt,Au) have demonstrated remarkable magnetic, electronic and optical characteristics.

Nanowires have potential applications in high-density data storage,either as magnetic read heads or as patterned storage media,  and electronic and opto electronic nanodevices, for metallic interconnects of quantum devices and nanodevices. The preparation of these nanowires relies on sophisticated growth techniques, which include self assembly processes, where atoms arrange themselvesnaturally on stepped surfaces, chemical vapour deposition (CVD) onto patterned substrates, electroplating or molecular beam epitaxy (MBE).

One-dimensional structures have been called in different ways: nanowires, nanorod, fibers of fibrils, whiskers, etc. The common characteristic of these structures is that all they have a nanometer size in one of the dimensions, which produces quantum confinement in the material and changes its properties.

Nanowires will be able to greatly reduce the size of electronic devices while allowing to increase the efficiency of those devices.Nanowires can be assembled in a rational and predictable because nanowires chemical composition, length, diameter, doping/electronic properties can be precisely controlled during synthesis.

Nanowires represents the best-defined class of nanoscale building blocks, and this precise control over key variables has correspondingly enabled a wide range of devices and integration strategies to be pursed.