It's a Central-Processing Unit (CPU), one of the fundamental components of a computer. AMD and Intel are the 2 biggest names in the industry as far as CPUs go. AMD has managed to build a reputation for itself due to manufacturing CPUs that are either similar or better than their Intel counterparts, albeit at a lower price.
Intel also wouldn't make anything larger than 4cores/8 threads (except for high end enthusiast chips which were ungodly expensive) and would charge a premium for it, then AMD comes out with a 12 core 24 thread cpu for cheaper than what Intel was producing
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