I think he probably means he can't drag his desktop with him to class every day.
Honestly, probably any good-quality laptop will serve you. I've personally owned Lenovo, Apple, and Dell laptops and have been satisfied with all of them, but my family has had some trouble with Dell laptops (probably because they bought from the less-expensive end of the spectrum). For me, the Apple was the nicest in terms of fit and finish, and at the time was a pretty good value for what I paid, especially considering the very-usable trackpad that Apple laptops use -- I still have and use it, even though its from 2008 (I've upgraded to 8GB RAM, and 256GB SSD), I just two weeks ago installed the latest OS X on it. But, the Lenovo certainly gave me more hardware bang for my buck, and I like it because I can dock it at home and use it with my nice keyboard and mouse, and three monitors (You can do this with many laptops, including Macs).
I say you want to look at 4-5 key traits:
- Screen size: too small a screen gives you too little room to work with and also usually implies that there's no physical or thermal room to have a higher-end processor or discrete graphics (there are some exceptions, mostly if you give up on also being thin), too large means you've got a bulky laptop that's hard to fit in a bag, and is likely heavy. I'd recommend something between 14 and 16 inches as a good compromise between physical size and utility.
- Screen resolution: Many inexpensive laptops still use 1366x768 screens which also limited the amount of room you have to work in. Its not even really sufficient for Visual Studio or another IDE, let alone Unity, let alone both Unity and and IDE. I wouldn't personally accept anything less than 1920x1080. My Lenovo is 1920x1080 on a 15.6" screen.
- RAM Capacity: For creating content, you probably want 8GB RAM minimum, and preferably 16GB. A content consumer can get by on 4 and should prefer 8, but keep in mind you'll be working with in-progress assets that are raw and likely uncompressed during development. In my lenovo, I have 32GB. Beware that many of today's laptops, especially thinner ones and 'ultralights' cannot have their RAM upgraded, you have to order what you want from the factory and be happy with it.
- SSD drive: I know you want a big, 1TB drive, but you should absolutely sacrifice that to get an SSD (even a modestly-sized one), if you have to. With USB3 or thunderbolt, an external spinning drive is just as fast as if it were inside your computer, and if your SSD is too small to store your music and video media, but you don't want to plug in an external drive just to listen to your tunes, a large, good quality SD card is plenty fast to stream music and video from. Luckily, many laptops today offer a 2.5" HDD bay, plus a small-form-factor SSD connector of some kind (either M.2, or mSata), so you have have both if you like.This is what I do in my Lenovo.
- Keyboard and pointing device: If you're going to spend a lot of time using it, you want a nice keyboard with a good, full-size layout -- and one which won't break from heavy use and/or is easily serviceable. My Lenovo would be super-easy to replace if it broke, literally a 3 minute fix, but my Mac not so much. Pointing devices are the same, you won't always have room to use a mouse so the track-pad should be at least passable. Mac's a head and shoulders above most others in the trackpad department, I have no trouble at all using it and found myself going without a mouse many times even when I had room (I could even imagine using it for a short Unity session). I don't like the Lenovo one so much, but it and the trackpoint nub are sufficient for web browsing and document/IDE tasks (though I wouldn't want to use either for typical Unity tasks).
Bonus -- Docking: And I mean real docking, not some lame everything-including-video-over-USB3 'solution' (thunderbolt would be fine, probably, as video transmits over the displayport link). Its really nice to come back to your office or dorm room or wherever and drop into a dock and instantly have several nice monitors (especially with Unity I find you want at least two screens -- one for Unity and another for your IDE), a great keyboard and mouse, a wired Ethernet connection, and maybe a DAS/NAS drive array.
For specific recommendations, I would say if money is not a great concern, consider a MacBook pro (though they're due to receive updates around June/July, most likely). The newest Razor Blade is similar in style and has a similar trackpad, and gets you more hardware for your dollar, so that'd be one to look at too. Otherwise consider a 'workstation-class' notebook from Lenovo (something like the W540 -- mine is a W530) or possibly HP (who's been making very solidly-reviewed professional products as of late).
If you're on a tighter budget, you can probably find something with lower-end discrete graphics, or an intel broadwell processor with HD5000-series graphics, or the last-gen intel Haswell processor with HD4000 graphics (preferable iris 4200 or iris pro 4600) which would probably be passible. If AMD had a lighter touch on battery life I'd recommend them, since their integrated graphics are twice as good as anything intel offers, but alas that's not the case with current APU products -- however, their next APU "Carrizo" is due very soon (< 6 weeks, likely) and supposedly increases performance 30% while cutting power-consumption by half. That would make them a competitive choice to intel -- the CPU will still be slower, but the GPU would embarrass intel's, so you could consider which kind of performance was more important to you.
would I need an SSD Drive? What differences would it change to a normal laptop? How would I install one ect. and what do you mean by Docking?, more monitors? Because if I were going for more monitors I would stick with my desktop, if im going to do hardcore game designing I would result to my Desktop but I want a laptop so when im away for like a week on a holiday I can still do some basic coding and work here and there, I might just have a laptop for coding and leave the modeling to my pc, if it works fast, well and is easy to use to develop game im fine with it.
EDIT:
I have had a look and I see what you mean with the thunderbolt ect. I don't think I would need a thunderbolt as I am not using a laptop for my life I use desktop and laptop for college and when im traveling so I think a basic laptop that can run my 3d games and make them would do.
You don't need an SSD, strictly speaking, but their advantages are numerous, to the point that I'd consider it bad advice to not recommend one, for all but the most budget-constrained configurations. A spinning disk has a read/write rate of around 90-130 MB/s, while an SSD today is going to be around 500MB/s read/write for a drive larger than 256GB (read will be the same for smaller drives, but write performance usually suffers, down to around half for 128GB or 64GB drives, which are too small to recommend anyways). Some m.2 and and PCIe SSDs will be even faster, an M.2 you might put in a laptop are yielding around 1GB/s read/write today. Spinning drives also have high seek times and suffer from file fragmentation, leading to less effective read/write -- SSD drives are basically immune to seek times and file fragmentation. After having at least 8GB of RAM, nothing will increase your computers responsiveness and "percieved performance" more than an SSD drive will. The difference between an SSD and spinning drive is night and day.
my Desktop has 1TB of Memory << not RAM
)... its usually not really exceptional, with the exception of one or two components (yes, there is always one component apple "pioneers" like the retina screen some years ago... paired to a weedy GPU. Nice)... the same can be had with PC Laptops for less, and quality of other manufacturers has really closed the gap to apple in the last few years.
