Well in some games the address changes every time you lets say you go to the next level or reset the game. It's sort of like a anti-cheat device. Pointer codes are codes that point to each code. So if you find the pointer code and offset(difference btw 2 codes) then you can use it to point to each code every time you go to the next level, etc.
Wow that still sounds confusing. Well let me try to show you an example.
Theres a game with levels.
Level 1
Address for Health
0x0000001
Your happy you found the code
Level 2
Address for Health
0x0000002
O No the address you found on level one doesn't work anymore.
Your choices are ether to go to every level and find the code for health on every level or use the pointer search to find the offset and point to every code from level 1 to level X.