Questions about a laptop.

Controller (Intel HD Graphics 530).= integrated graphics
Discrete graphics adapter model (GTX 950M) = video card

You can use either, but obviously you'd prefer the 950M.

Also, looking at the laptop, would it be a good laptop for gaming?

Meh, depends on your standards. I'd get something with a beefier GPU than a 950M - at least a 960 or 1060, especially for 1080p (and those particular games). 256GB isn't much in the way of storage, either. That's a decent enough SSD, but a HDD to complement it would be nice as well.

Normally laptops use these graphics cards for power saving and performance.here Intel acts as a power saving one.when you normally use laptop for movies or browsing etc Intel will be used.when you are gaming Nvidia will kick in for performance in gaming.this is known as switchable graphics cards.it is done via Nvidia drivers.you can even individually specify which graphics card to use for which application.
Inshort Intel uses less power so more battery backup,Nvidia uses more power and gives performance so less battery backup
Regarding the above mentioned laptop it depends on your budget and needs.

GTX 950M
would it be a good laptop for gaming?

No.

For a gaming laptop running Windows 10; Don't get a laptop with anything less then 16GB of ram (I've seen Win10 eat nearly 8GB just on startup), and make sure it has an SSD since laptop mechanical drives are even slower then desktop ones. For the GPU, a Geforce 1050 or better would be ideal not just because of the performance but because the Pascal series runs cooler and uses less power then previous generations.

https://www.notebookcheck.net/Mobile-Graphics-Cards-Benchmark-List.844.0.html

not much to choose anyway:
latest i7 + min. 8GB RAM, SSD, 1080p display - i wouldn't go for less than a GTX 1060
with 1080p displays a GTX 1050 Ti would get close but its still considerably less capable

as usual timings kinda bad - intel's about throw out their
coffee lake cpu's next month or so ... stuff might be cheaper then

View attached image.

http://www.game-debate.com/games/index.php?g_id=1308&game=Grand+Theft+Auto+V&popSysReqRAM=8&p_make=Intel&p_deriv=Core+i7-6700HQ+4-Core+2.6GHz&gc_make=Nvidia&gc_deriv=GeForce+GTX+950M+2GB&ram=8&checkSubmit=#systemrequirements

You can play GTA V.

These laptops should come with 1366x768 or 1440x900 panels and just upscale to 1080p for video with HDMI. The cost would be better and those 2 resolutions are good for the GTX 950. I don't know how much performance loss has a laptop GPU (probs between 10-15%). It may be enough for 1080p with all settings at low.