Solder :
Alloys fused and applied to the joint between metals to unite them without heating the metals to their melting point.
Patina:
Surface calcification produced by oxidization on the surface of metals. Makes your piece look antique.
Pickle:
an acid/chemical solution that metal objects are dipped in to remove oxide scale or other substances. "Cleans the metal"
"Flow" solder:
A technique used to fuse solder to a flat piece of metal.
Sweat Solder:
Technique used to fuse two pieces of metal together by pre-coating with solder and merging them with the application of heat.