If you are looking for a more cost-effective processor, AMD processors may be the best bet. For students, budget gamers, and individuals with straight-forward computing needs, AMD processors are a great choice – they are powerful and fast enough for most while undercutting competitor pricing. And yet, you give up little when going with AMD chips. They can be "overclocked" for increased speed, provide robust and vibrant graphics, and are available in multi-core setups for multithreaded performance.

On the higher end of the spectrum, Intel processors shine. If you are seeking performance that is at the upper range of the market, there is sure to be an Intel chip that suits your needs. You may pay more for it, and you may give up flexibility for this performance, but the processor itself will provide you with lightning speed, incredible capability, and beautiful graphics. In terms of outright power, it's hard to beat Intel processors.

Source: ShopLenovo.com

Intel Celeron & Intel Pentium Processors
Both of these are budget brand names, and processors in both lines tend to be differentiated by clock speed and not much else. Skylake Pentiums are G4000-series chips, while Celerons are G3000-series. They’re all dual-core CPUs with no Turbo Boost, no Hyperthreading, and 3MB of cache, and they’re typically paired with the basic Intel HD 510 integrated GPU.

Core i3 CPUs are a little faster, but Pentiums will give most price-conscious people the best bang for their buck.

Intel Core i3 Processors
These CPUs are still dual-core but add Hyperthreading, which presents two logical processor cores to the operating system for every physical core. This can definitely help performance in multithreaded workloads, though it’s nowhere near the boost you’d get from moving to a quad-core CPU. Core i3-6100 CPUs include 3MB of cache while 6300-series chips include 4MB of cache; nearly all of them use the Intel HD 530 GPU.

Intel Core i5 Processors
These are all quad-core CPUs without Hyperthreading, and they probably represent the best balance of price and performance for high-end users. They also use Intel’s Turbo Boost feature, which let the CPU run at higher clock speeds when there’s enough thermal headroom or when fewer cores are being actively used. Not all workloads will benefit from two extra processor cores, but video editing, Photoshop work, and an increasingly large number of games are all happier with four cores. All of these CPUs include 6MB of cache and most of them have Intel HD 530 GPUs.

Intel Core i7 Processors
These are best described as Core i5 chips with Hyperthreading, higher clock speeds, and and 8MB of cache. Otherwise they’re the same. As with Core i3 CPUs, Hyperthreading definitely does help performance in heavily threaded programs, but jumping from a Pentium or Core i3 to a Core i5 will get you a much larger performance bump than jumping from an i5 to an i7.

Source: https://arstechnica.com/gadgets/2016/02/pentium-core-i5-core-i7-making-sense-of-intels-convoluted-cpu-lineup/