There are two views of the motherboard. By default when the link is clicked on, the Bottom view is the large main view.
(In the two views shown, it is the view on the Left )
Looking at the Bottom View;
1) The Pink(?) square socket you see at the top is the Processor socket.
(CPU - Central Processing Unit. Another term used is Microprocessor, or simply Processor)
It is a Socket P mobile processor socket,http://en.wikipedia.org/wiki/Socket_P
Dell gives you options, so it's hard to say what Intel processor is on your motherboard.
The Intel GM45 mobile chipset, supports mobile processors that are Intel Core2 Duo, Intel Core2 Extreme, and Intel Celeron M.
A 667MHz, or 800MHz, or 1066MHz FSB is supported.
I have seen an Intel Core2 Duo, model T6400 offered, so I know it supports using a Socket P processor socket, uses a 1.00 to 1.250 voltage range (DC), and the Penyrn-M Core, and 45nm technology,http://en.wikipedia.org/wiki/List_of_Intel_Core_2_microprocessors#.22Penryn.22.2C_.22Penryn-3M.22_.28standard-voltage.2C_45_nm.29
Laptop disassembled the easiest way to find out, is to put an ESD wrist ********, connect it's alligator clip to a good ground source, and look at the Processor.
GENTLY use an old credit card, to scrape off as much if the thermal paste as you can, then use Q-tips dipped in Isopropyl Alcohol.
(Takes a bunch of alcohol soaked Q-tips)
Look for the sSpec Number, and the Part Number. Then 'google' it.
Isopropyl Alcohol is EXTREMELY FLAMMABLE!
Use in a WELL ventilated area with NO sparks, or flames present!]
Laptop together, functional, and internet ready, use CPU-Z from CPUID.com to find out.
3) Below the pink Socket P processor socket is part of the motherboard chipset.
The Northbridge chip.
It is an Intel GM45 chipset, it is an SMD (Surface Mount Device), and uses a BGA surface mount,http://en.wikipedia.org/wiki/List_of_Intel_chipsets#Core_2_mobile_chipsetshttp://www.ebay.com/itm/NEW-1X-Intel-AC82GM45-QV08-ES-Chipset-With-Balls-2010-/221068892458?pt=LH_DefaultDomain_0&hash=item3378bb992a
BGA surface mount.
Ball Grid Array surface mount.
View a BGA Rework Station in use, and learn in detail what a BGA surface mount is,http://www.ersa.com/art-ir-pl-650-346-1472.html
Scroll down, click on the red - Take a few minutes to view the IR 650 video demo
The Southbridge chip is an Intel 82801IMB, (ICH9-M)
It's on the Top of the motherboard.
[Chip and Chipset are slang terms for I.C.
(A Processor is an I.C.) ]
The motherboard chipset is the Northbridge chip, and the Southbridge chip.
(Does Not apply to motherboards that support the Intel Core i3, Core i5, Core i7, and Core i9 processors)
The Northbridge chip handles the Faster capabilities of a computer.
The Processor, Ram Memory, and HIGH-speed graphics.
AGP (Accelerated Graphics Port), and PCI-Express, are High-speed graphics.
A graphics card using a PCI expansion slot, and Integrated graphics, is Not high-speed graphics.
[Integrated Graphics used to be referred to as OnBoard Graphics.
ON the motherBOARD. Easier to understand ]
The Southbridge chip handles the Slower capabilities of a computer.
1) Anything connected to the PCI bus.
PCI expansion slots, or OnBoard Graphics.
2) Anything connected to the IDE bus
3) SATA bus
4) USB bus
5) Ethernet bus
6) Audio (Sound)http://en.wikipedia.org/wiki/File:Motherboard_diagram.svg
[CPU = Central Processing Unit. Another term used is Microprocessor, or simply Processor, for short ]
As you can see Serial Ports, Parallel Ports, Floppy Disk drive, the Keyboard, and Mouse, are connected to the Super I/O chipset.
[I/O = Input/Output. Input and Output devices ]
I do not know what Super I/O chipset is used.
You may want to look through this chart, and see yours matches up with one of them, (They are probably too old, but gives you an idea of what to look for),http://web.archive.org/web/20070929033214/http://www.esupport.com/techsupport/award/superio.htm
There are Two Ram Memory slots. (Seen on bottom of motherboard)
Maximum Amount for each Ram Memory slot is 4GigaByte.
Maximum TOTAL Amount is 8GB.
Uses DDR2 Sdram that is SO-DIMM.
(Small Outline Dual Inline Memory Module)
Smaller in size than desktop computer DIMM.
Can use either DDR2 Sdram at 667MegaHertz, or 800MHz.
(PC2-5300 and PC2-6400, respectively)
Uses a 2.5 SATA harddrive.
Continued in an added Comment.