With that in mind, there are a few guideposts you can use to understand what all the different parts mean.
This is generally meaningless, though, as the newer part is still going to perform better-check out this comparison at UserBenchmark as an example. For example, a seventh-generation “Kaby Lake” Core i7, and a third-generation “Ivy Bridge” Core i7 might run at similar speeds with similar core counts. Therefore, the differences between Core i3, Core i5, and Core i7 designations matter most within its respective generation.