Correct pointer i points to x. Just like you said.
I think pointers are among the most usefull things in c.
You can allocate pieces of memory and use a pointer to access the memory. You can use pointers to manipulate arrays, structures all kinds of things. You can also use function pointers.
Play around with it. Look at various examples on the web:
www.codeguru.com www.codeproject.com. Warning: those sites are very win32.
Good luck