Intel® Core™ i5- vs core 2 duo - Core - Components

i would like to know wich processor is better..... intel i5 or core 2 Duo??? cuz i'm planing to buy a vaio notebook with the core i5, but i've heard that core 2 Duo is the best, so i want to know if the core i5 is beter, worse or if both are similar. Here

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