A Central Processing Unit.

It's in every computer, and is often referred to as the “brain” of the computer if we're giving it a comparative analogy. Its true definition in its simplest form is it’s a computer chip that handles data from other parts of the system, just like how your brain processes data from your eyes, limbs, and nose.

Not all CPUs are created equal though, some can do things better than others. There are so many models out in the market it can be fairly confusing to choose the right processor, but thankfully Intel's naming conventions make it easy to identify the best CPU for your needs.

So which processor is the best? It's really tough to say, and it varies depending on who you ask. In general, Celerons, Pentiums and Atom processors are considered budget friendly but don't offer the best performance. While the i3, i5, i7, and more recently the i9 series can really push computing to the max. Intel i9 Processors are usually better than i7s and i7s are usually better than i5, which in turn are better than i3, which are better than Celerons and so on.

These tiers all come at a price – but one can argue that the performance gain from i5 to i7 may not be worth the additional investment.

Before we talk about the class of processors, lets define a few keywords that identify the performance of the CPU

Definitions:

Celerons, Pentiums, and Atoms(X5 X7) : For Basic Needs

These processors are usually found in very low- to low end machines. Typically speaking if your laptop or computer is purchased from a retail store and costs less than $250. It's probably running one of these budget CPUs. These processors may have an average to high clock speed, but lack in cores. It may only be capable of handling one task at a time. They generally will struggle with multitasking – so no video gaming, while watching a movie.

They're great for students, who do not need an entertainment media machine. Although more modern versions of these CPUs may be able to run some high quality media, it may start struggling to run media at the highest end of the spectrum. These CPU's usually cost (or add to the price of a computer) $50-$100.

i3: When basic isn't enough

This class of processors is the first of Intel's performance line. They're still considered budget friendly, in fact they can be found inside laptops and computers in the $250-$400 range. Intel i3s generally have high clock speed, but usually have only 2 cores in them (some newer models have 4). There are some limitations to how much RAM you can have with an i3, for example an i3-7100T will only allow for a max capacity of 4GB, but thankfully this is only true with some models, and not all. It has enough under the hood to outperform Celerons, Pentiums and Atoms – so it's use in the real world is a staple for workstations, consumers who do a little bit of multitasking, and even media servers that run programs like PLEX.

This processor may be perfect for those who are willing to pay a little bit more for about a 20-30% increase in performance. Although some i3 CPUs can even output 4k resolution (Super HD), It's not optimal, but you should be able to transcode 720p and view 1080p content perfectly fine.

i3s typically cost (or add to the cost of a computer) $75-$150

View – I mean this in a sense where you can watch HD content in 1080p like YouTube.

Typical Users: Students, Office Employees

Example CPUs:i3-3220

i5: The "You can't go wrong with an i5" Processor

This class of processor is probably the most common because it offers a balance between performance and cost. Most i5 processors have an average to high clock speed, with up to four cores (with the exception of the i5-4570T Processor). This makes it a great all around CPU where it can perform just about everything well, but it certainly won't blow you away. You can render 3d models at a decent time (not the fastest) watch super HD content, play video games, create videos and music much better than processors before this. This processor is standard for most enthusiasts and can give a power user (someone who uses the computer more than the average office worker) the benefit of faster performance.

You can find this processor in computers ranging from $400-$700

an i5 typically costs (or adds to the cost of a computer $150-$250)

Typical Users: Power Users, Enthusiasts, Gamers

Example CPUs: i5-2400

i7:  The old king of processing

i7's were revered as the king of consumer grade performance CPUs (up until i9 processors came out) These CPUs usually have 4 cores, but use hyper threading technology – which essentially doubles the performance of multi-tasking applications like in transcoding, and rendering. Although i7's have 4 physical cores on them, hyper threading allows it to operate like it has 8!

This performance comes at a cost though, they're generally much more expensive than i5s, and the non-multi-task-specific applications don't really receive much benefit from 8 cores. Infact, if you don't even use applications that make use of multi-core processing, your experience with i5s and i7s would be fairly similar.

But still, if you want performance the i7 processor was the way to go – up until recently.

You can find this processor in computers ranging from $600+

an i7 processor typically costs (or adds to the cost of a computer $200-$400)

Typical Users: Enthusiasts, Computer Science / Graphic professionals, Gamers

Example CPUs: i7-3770

i9: The New King

Lastly the final class of consumer grade processors is the i9 series. These processors have a very high clock speed, with a very high core count with hyper threading. It's literally the best of the best, but usually requires a completely  different kind of system to support this archetype. These types of processors are hybrid server/desktop grade – allowing you to completely tip the scale in performance. However, they are not cheap and is recommended that you only purchase these during a sale.

You can find this processor in computers ranging at from around $1500

This CPU can cost up to $800+ alone, and adds about $1000 to the cost of the computer if buying retail

Typical Users: Top 2% of consumers.

Example CPUs: i9-7900x

Generations

On top of all of this information I've provided, there is one more important piece of information you must know about these processors. A lot of what we covered, especially when talking about CPU specifications, only apply to the same generation. For example, an i3- 2100 which has a clock speed of 3.1 GHz, is much slower than an i7- 6600u that has a clock speed of 2.6ghz. 2 ^nd generation processors ( which can be determined by the first number in the model number) operate much differently than 6 ^th generation processors. I’ve bolded the numbers to tell you where to look. So when comparing benchmarks, you should only look at CPUs in the same generation.

Fun Side Note: There is no particular reason why intel chose the numbering convention i3, i5, and i7!