Solid wire consists of a single strand (or core) of wire that is insulated with a non-conductive material and is prone to break easier and does not create as good of a connection as stranded wire. Stranded wire consists of a bundle of small gauge wires compressed and insulated with a non-conductive material. Stranded conductors are excellent for applications that call for repeated flexing without damaging the cable.
Stranded wire conductors are preferred for:
Conductor flexibility is much greater in stranded conductors, making them easier to install.
Flex life is longer compared to solid conductors. Stranded conductors can endure more vibration and bending before breaking. Generally speaking, the finer the stranding, the more flexible the conductor.
Damage to stranded conductors, such as scratching or nicking, will be less serious than similar damage to solid conductors.
Strand count affects both the flexibility and cost of a conductor. For any wire size, the more strands present, the more flexible the conductor becomes.