Hi Akash,
As the other two posters have mentioned.
When a new node process is created for smaller creation in Nm Nano meter scale for transistors, and integrated circuits.
It means you can pack more of a transistor count into a smaller required space to create the cpu.
The more transistors you have or can create in a given area or scale the more powerful the cpu will be.
Also due to the size decreasing of each transistor the power consumption of the over all cpu is reduced.
When it comes to a cost for new technology, or cpu`s you will always pay a premium price.
This is due to the fact that the smaller the Node process the more harder or likely it is that you will get production yield problems when producing a cpu on a set Nm scale.
The percent of working cpu dies that are fully functional as intended, vs the amount of cpu dies that fail when a silicone wafer is created with many cpu dies on it.
reflects on the end price of what you will pay for one working cpu of a set speed or generation in the road map of future cpu`s that come to market.
Say you had a yield rate of a 10Nm cpu rated as a I7 or an extreme model of Intel cpu that worked at 6 Ghz speed.
But for each silicone platter or substrate used to create the cpu`s could fit up to 250 cpu dies on it.
And out of each silicone platter only 5% of the total yield produced from one silicone platter resulted in a I7 or an extreme model of Intel cpu die that worked at 6 Ghz speed.
Then the cost of that model of cpu would be more expensive to you the buyer of it. Due to a low quantity count for that model of cpu in the range.
If the successful yield percentage improves. then it off sets the price of each cpu die or wafer created that can be used from the silicone platter.
When a new process is created for a new line or generation of a cpu range.
The price when first released is always more expensive for that model of cpu created.
But as time goes by they perfect the process so the working yield percentage of a set cpu die increases.
Then the price of the cpu over time will lower in cost.
And Cpu dies that don`t make the grade for a set model number or range of cpu of a silicone platter where it may hold up to 250 cpu dies.
Go through a process of testing where depending on how functional each cpu die is.
It is re bagged as a lower end model of the cpu range, in the speed it can run at, but also the model.
Example a I5 cpu instead of a I7 if part of the cpu is not fully functional in transistor count.