i am trying to use gdb to analyse a c program but i am a little confused. in the above picture you can see i am trying to analyse the stack . On the left we have memory addresses.Since i am using a 64 bit machine ,shouldn't ever memory address have 64 bits?but in the picture every memory location has 32 bits . Also the stack starts at 0x28fed0 and the second address is 0x28fee0 ,where are the address between these.I mean where is 0x28fed1? I studied architecture many years ago and i seem to be missing something basic. Can any one help me out?