What is the difference between gcc -ggdb and gcc -g

Question

When I use gcc to compile C programs I usually use -g to get some debug information into the elf file so that gdb can help me if needed.

However, I not

Answer 1

This is the official explanation: http://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html#Debugging-Options

Only few hard facts, but interesting anyway.