a coredump is basically a dump of everthing in your program space's memory block - the values of all the variables, everything on the stack and on the heap, etc. they're very cryptic and hard to read, although they used to be the ONLY way to debug stuff.
coredumps usually occure when you use memory you shouldn't - i.e. writting too much to your character array in a C-style
string, de-referencing a pointer that isn't set right...
They can be very hard to track down. If it happens often, or you can figure out how to trigger it, you can throw a bunch of logging in your program and run it. See what the last statement logged is, and that will help you narrow down where the problem is.
