Whats better 120GB (5400RPM) or 120GB (7200RPM) Free Fall Sensor? And what is the difference?

Also what is better ... CD Writer / DVD Player (Combo Drive) or CD / DVD Writer (DVD+/-RW Drive) And whats the difference. What can each one do that the other can't?

What does 2GB Shared Dual Channel DDR2 at 667MHz mean?

the 7200 RPM drive is faster, but will lower the battery life at the same time. So you'll need to determine if you want more battery life or Windows to load 3 seconds faster.

DVD Writer beats a combo drive. You can't write DVDs with a combo drive.

2GB shared Dual Channel DDR2 at 667 MHz - a breakdown of this phrase -
-2GB is the total amount of RAM
-shared means that the computer uses at least 64 MB of that memory for video card functionality. Whatever operating system you use won't be able to access the portion of the memory being used for video.
-Dual Channel means that you have 2 sticks of matched memory that can be accessed at the same time.
-DDR2 is the technology of the RAM. DDR2 is a Quad-pumped memory technology, meaning that 4 memory operations happen with every memory clock cycle.
-667 MHz is the rated speed of the RAM.

120GB (7200RPM) would be better.

It works at a faster speed, collecting data faster.
Notice the 5400 versus the 7200.

I'm not sure for the second or third one.

7200 RPM spinns faster therefore should have faster transfer speeds than 5400 drive.

first optical drive can only read DVDs but can read/write cds, second drive can readwrite bot cds and dvd. get the second drive.

Not sure what your question on the memory is? the memory runs at 667 mhz

First off the 120GB 7200 RPM is fast because the disks spin at 7200 RPM. The free fall sensor is exactly what it is, its a g-force sense that can tell if it is falling and stops the drive so it doesn't get damaged from the drop.

The second drive u mention can write data onto DVDs which the first one doesn't, it just plays the DVDs.

The RAM u mention is 2GB worth of DDR2 memory. It's clocked at 667Mhz and is dual channel meaning it can be used by multi-core processors and overall speeds the computer up if it weren't Dual channel.

you want the 120gb (7200Rpm) -its a faster hard drive, and hard drives are normally one of the slowest parts of your computer, so you want the fastest RPM.

the CD/DVD Writer is better - you can burn and view both cds and dvds (the cd writer /dvd player you can only burn cds and you can only view dvds)

2Gb shared dual channel DDR2 at 667MHz means that you have 2GB of ram running at 667mhz, the kind of ram you have is DDR2. if after that it says "2 dimms" it means the 2Gb of ram you have take up 2 sockets in your computer- therefore meaning you have two 1gb sticks of ram. It could also say "4 dimms" mean it would be in 4 sockets- meaning you have four 512mb sticks of ram. If its not that much more, you really want the 2gb in 2dimms or it may be expressed as (2 x 1GB).

it looks like someone is getting a new computer
hope this helps