The processor, commonly known as CPU, is the beating heart of a PC. Unlike other components (such as memory), upgrading a processor at a later stage can be difficult and expensive. Consider your current and future performance requirements when choosing.
AMD vs. Intel - This is a common question that we are asked on a daily basis. Intel currently has the performance advantage over AMD with its excellent 6th Generation 1151 processor range, which offers very high performance and great value-for-money.
CPU frequency - The frequency of the CPU, usually measured in Ghz, shows the speed of the internal core of the CPU. This isn't the main performance indicator, you should also look at the cache and the amount of cores the CPU has.
Cache - Used by the central processing unit of a computer to reduce the average time to access memory. The cache is a smaller, faster memory which stores copies of the data from the most frequently used main memory locations.