How many generation are there for intel core i3 , i5 and i7 ?

below picture is a list of all ganaration with their codename their nanometers and their Graphics

 

 

Here are listed down in the table

I agree with danish Shafiq answer.

You differenciate them by the1er digit of the model:

- Core i3-xxx :1st generation

- Core i3-2xxx :2nd gen

- Core i3-3xxx :3rd gen

- Core i3-4xxx :4th gen

 

- Core i3-5xxx :5th gen

- Core i5-xxx :1st gen

- Core i5-2xxx :2nd gen

- Core i5-3xxx :3rd gen

- Core i5-4xxx :4th gen

- Core i5-5xxx :5th gen

 

- Core i7-xxx :1st gen

- Core i7-2xxx :2nd gen

- Core i7-3xxx :3rd gen

- Core i7-4xxx :4th gen

- Core i7-5xxx :5th gen

Digits xxx serve to differenciate processors of the same model and same generation : The higher xxx is, the more performant processor is.

 

Actually, intel is commercializing the6th generation.

As my knowledge they reach the 7th generation for each

fourth-generation" or code-named "Haswell."

Looking at the current Haswell lineup, we have Core i3 processors ranging from suggested retail prices of $122 to $149, Core i5 chips priced from $182 to $242, and Core i7 parts set between $303 and $339. Of course, there are Haswell-E chips for $389 to $999, but let's not worry about those for now.    

 

All the following three Core processors are based on the same architecture so where they really differ is in their number of cores/threads and cache size. There are other factors such as operating frequency and integrated graphics, but for the most part it's the cores and cache that matter.       Intel keeps on improving its processor products like, with time and devices the i-Series have generated multiple number of processor within that class. The Intel i-Core generation has launched its latest 5th Generation processor.

intel i3 i5 i7 processor chart

https://en.wikipedia.org/wiki/Intel_Core

thanks for the invitation.

Agree with the answer of Danish Shafiq.

thanks Mr. Danish Shafiq for complete and detailed explaination in one picture its realy time saving efforts.