Its not a dumb question and basically you have the right idea.
Fusing is exactly the same thing as welding steel. You put two
pieces of metal against each other and heat the edges of both to
the melting point. When it melts the metal of each side will flow
into a pool of molten metal in the middle. Take away the heat and
it will harden into a single piece. It is really much simpler
than the explanation.
Give it a try on some scrap metal. Butt two pieces of metal
together and heat them with a small, hot flame. The metal should
melt along each side and flow together. It takes a bit of
practice but is really not very difficult. It works best on
metals with low thermal conductivity such as 24K gold or
platinum. Use a very hot, small flame so you melt only the metal
along the seam. You only want to melt a small amount of metal.
The most common mistake is using a flame that is too hot or too
cold. When you do this you tend to melt a large part of the metal
rather than just that along the joint. Hope that I have been of