Jewelry wire comes in different gauges. Gauge is basically the thickness of the wire. The smaller the number the thicker the wire. A typical size is 16 gauge, while 28 gauge is much thinner
Jewelry wire comes in different hardnesses. The harder the wire, the harder it will be to bend and shape the wire to your needs. A dead soft wire can be easily shaped with your fingers while a full hard wire needs special jewelry tools such as pliers.
Jewelry wire also comes in 3 different shapes which are round, half round and square. You can tell which type of wire you are working with simply by looking at the shape.
When working with jewelry wire you will need some basic wire tools such as a wire cutter, round nose pliers, flat nose pliers, chain nose pliers and wire straighteners.