help with tool jointing?

So I'm trying to learn how to make a tool with several parts besides the handle. I figured out that to do this you need to make joints within the parts of the tool. I tried reading the wiki on this, but it was very confusing and I didn't really understand it. Can someone give me an easy explanation of how I could create joints to make a tool with more than just a handle?

Alright to make a tool with more then one part you can use welds the following script is an example of two parts in workspace it's just a script that makes a weld between two parts that I will create in the script. Look at my example here:-

Local p1 = Instance.new("Part", workspace)
Local p2 = Instance,new("Part", workspace)
Local weld = Instance.new("Weld", p1)
weld.Part0 = p1
weld.Part1 = p2
weld.C0 = weld.C0 * p1.CFrame:inverse()   --Not sure about this one but, goes something like this...

What is the part0 and part1 and c0 and c1?