Decoding the code

Everyone of us know about the basic processors used now a days that is Intel core i3, i5, i7. But each on them has a wide variety. For example the core i5 has 50 to 60 variants. let's take i5-4200m, here "4" denotes the generation of the processor. "m" denotes that it is a mobile CPU. Hence used in laptops. The i5-4200 is used in desktop PC's.

Similarly every model number denotes the CPU's speciality. Here are some of the common Alpha Suffix:
C - desktop processor based on LGA 1150
M - mobile CPU
QM - quad core mobile
K - unlocked CPU
S - Performance optimized
T - Power optimized
U - Ultra low power
Y - Extremely low power
The "k" processor is used to over clock the CPU i.e. to increase the clock speed. Used in high performance workstation or gaming pc's. The "u" processor provides optimal performance for everyday work but does not perform well for gaming due under clocked processor. Every CPU is made for a specific use.
There are also many misconceptions when comparing two processors. The performance of every CPU does not merely only depend on its clock speed, but also on its number of core, threads and power consumption. A processor consuming low power will provide low power but provide extended battery life.
Similarly, when comparing a i5 or i7, the winner can be decided on the basis of work to be done by them. For example if the a user uses MS word on a computer with i5 or i7, he or she wouldn't notice any difference. Many application do not use multi-cores, they use only single core. So here a multi core and single core processor may perform equally well. In some cases a i5 can outperform a i7. This is due to the architectural difference between both. So a CPU should be bought on the basis of requirement by the user.

A GPU (graphics processor unit) can be integrated or external (graphic cards). The CPU have integrated GPU like Intel HD graphics which are okay for everyday use, but are nowhere when compared with graphics cards of Nvidia and AMD.

There is some misconceptions when comparing two graphics cards. They can't be compared merely on their memory size like 1 GB, 2 GB etc. Graphic card are compared on basis of their cuda cores, clock speed, memory size, memory type etc.
Let us take nvidia's graphic card as an example. Nvidia has geforce series for gaming purpose. Every year a new generation is introduced. One such generation is the 9th gen. The models vary from 910 to 990. 910 being the lowest and 990 highest in terms of both price and performance.

The graphic cards used in laptop are mobile GPU. They consume low power and hence deliver lower performance than pc. They are denoted by letter 'm' at the end of the model. Example Nvidia geforce 950m is a GPU for laptop.
910-930 models are used for entry level gaming. 940-950 models are used for mid level gaming and 970 and above provide high level gaming experience.
In some pc or even laptop two or more than two graphic card can be installed. This is the SLI technology of Nvidia which combines the power of both cards and produces a single output.
Graphics card are used for gaming, 3D visualization applications, Larger display environments etc.