That's easy. Intel only does integrated graphics which are always subpar compared to a dedicated GPU. However, that really only matters if you're gaming or doing some kind of high end video editing with GPGPU functionality. Odds are if you fit into either category, you'd already know this and wouldn't need to ask the question any more than you'd even be considering a Celeron or Pentium based unit, so I'd say don't worry about it. Intel graphics are generally good enough and because they're generally so underpowered relative to nVidia and AMD offerings, they're much more battery friendly on laptops.
The laptop I'm planning to buy is "Probook 440s" (which is the new model of 4440s ) My choices for graphics card are:
Integrated: Intel HD9 Graphics 4000 (3rd Generation Intel Quad—Core 17 and Dual—Core i5 and i3);
Intel HD9 Graphics (Celeron and Pentium configurations)
Discrete: AMD Radeon™ HD9 8750M, with 1 or 2 GB dedicated DDR3 video memory11
My research over the internet has given me the impression that Intel is the best.. but out of the above three graphics cards, dedicated memory comes only with the AMD.
So, which one should I opt for ?