From Wikipedia:

Wire sculpture refers to the creation of sculpture or jewelry (sometimes called wire wrap jewelry) out of wire. The medium was experimented with by Alexander Calder.
Because the needed tools are simple, wire sculpture can be learned and performed in home studios by hobby artists.
Some of the tools used include pliers, pin vises, file, wire cutters, and mandrels.
The wire used may be of a variety of decorative metals in different cross-sections. Wire sculpture jewelry may have beads or gemstones integrated into the design.