What's the difference between an Intel Core i3, i5 and i7?

We've seen many years now of Intel Core i3, Core i5, and Core i7 CPUs releases but most consumers are still asking the same kinds of questions. What's the difference and is it worth paying more for a CPU with more cores?

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What is a Core i3, Core i5, or Core i7 as Fast As Possible

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Differences between the three Intel family i3, i5 and i7

What's the difference between an Intel Core i3, i5 and i7?, intel

Intel Core i3 vs i5 vs i7 vs i9: What's The Difference?

What is the difference between Intel Core™ i3, i5, i7 and i9 processors?

Intel i3,i5,i7; What's the Difference?, News & Events

What's the difference between an Intel Core i3, i5 and i7?, intel