Are you asking for a quick answer on how Apple computers differ or were you wondering if you get some better hardware for the buck on the Windows based machine?
-> But here's what I suggest. Go to the open houses and see what the majority is using. Both machines can get the job done.
I will be attending college in the fall as a biology major and my school has offers on two laptops, and I was wondering which one would be the better choice, they both cost $1300 and I will not be gaming on these laptops.
The first is an Apple Macbook: 2.4GHz Intel Core Duo Processor 2GB Memory 13.3" Glossy Display 160GB Hard Drive SuperDrive CD & DVD Burner Built-in iSight Camera Mac OSX 10.5 Leopard iLife '08.
The second is the Dell XPS M1330: Intel Core 2 Duo T8300 (2.4 GHz/800 MHz FSB / 3 MB cache)
13.3" Slim and Light LED Display with VGA Webcam
4GB shared Dual Channel DDR2 SDRAM at 667 MHz
250GB SATA Hard Drive (5400RPM)
CD/DVD burner (DVD+/-RW Drive)
128MB NVIDIA GeForce 8400M GS
Genuine Windows Vista Home Premium Edition SP1