A mechanical keyboard is a type of computer keyboard that uses individual mechanical switches for each key, instead of the rubber dome switches that are commonly used in traditional keyboards.

These mechanical switches provide a more tactile and responsive feel than dome switches, which can be beneficial for typing and gaming.

They also tend to last longer than dome switches, which makes mechanical keyboards a more durable option. Some people prefer mechanical keyboards because they can be customized with different switch types to suit the user's preferences.

Mechanical keyboards come in a range of sizes, from compact and portable to full-sized and feature-packed. The most common sizes of mechanical keyboard are:

Full-sized - This is the largest size of mechanical keyboard, and it includes the alphanumeric keys, the function row, the dedicated navigation keys, and a numeric keypad. It is the most feature-packed and versatile size, but it is also the largest and heaviest.

TKL (tenkeyless) - This size includes the alphanumeric keys, the function row, and the dedicated navigation keys, but it does not have a numeric keypad. This makes it smaller and more portable than a full-sized keyboard, while still retaining most of its functionality.

75% - This size includes the alphanumeric keys and the function row, but it lacks the dedicated navigation keys that are found on a full-sized keyboard. It is a good compromise between compactness and functionality.

65% - This size includes the alphanumeric keys, as well as some additional keys, such as a number row and navigation keys. It is slightly larger than a 60% keyboard, but still compact and portable.

60% - This is the smallest standard size of mechanical keyboard, and it only includes the alphanumeric keys. It is compact and portable, making it a good choice for people who need a keyboard that is easy to take with them on the go.

40% - A further minimization of a 60%, using less keys and less space. Usually shrinks modifier keys and removal of the number row. 

Split - Usually the smallest and mostly for ergonomic purposes, these mechanical keyboards use staggered or ortholinear layouts to be as comfortable and compact.

Again, the best size for you will depend on your personal preferences and needs. Some people prefer a compact keyboard for portability, while others prefer a full-sized keyboard for its added functionality. It's a good idea to try out different sizes to find the one that works best for you.

Linear, tactile, and clicky are three different types of mechanical keyboard switches that are defined by the way they feel and the sound they make when you press them.

Linear switches are smooth and consistent, without any tactile feedback or clicking sound. They are often preferred by gamers because they allow for fast, uninterrupted keystrokes.

Tactile switches have a small bump or resistance that you can feel when you press them. This provides a little bit of feedback, letting you know that the key has been pressed. Tactile switches are popular for both gaming and typing, as they offer a good balance between speed and feedback.

Clicky switches are loud and have a distinct clicking sound when you press them. They provide both tactile and auditory feedback, which can be helpful for typing but may be too noisy for some people.

Again, the best type of switch for you will depend on your personal preferences and needs. Some people prefer linear switches for gaming, while others prefer tactile or clicky switches for typing. It's a good idea to try out different switches to find the one that works best for you.

There are several different types of mechanical keyboard switches, each with its own unique characteristics. Some of the most common types of switches include:

Cherry MX switches - These are the most popular type of mechanical keyboard switches, and they come in a variety of colors that represent the different characteristics of each switch. For example, Cherry MX Red switches are linear (non-tactile) switches that are popular for gaming, while Cherry MX Brown switches are tactile switches that are good for both gaming and typing.

Kailh switches - Kailh switches are a newer type of switch that are often compared to Cherry MX switches. They come in a similar range of colors and offer similar characteristics, but some people find them to be slightly smoother and more durable than Cherry MX switches.

Gateron switches - Gateron switches are another popular alternative to Cherry MX switches. They are known for their smooth, consistent feel and are often considered to be a good value option.

There are many other types of mechanical keyboard switches on the market, and the best type for you will depend on your personal preferences and needs. Some people prefer a linear switch for gaming, while others prefer a tactile switch for typing. It's a good idea to try out different switches to find the one that works best for you.

To build a mechanical keyboard, you will need the following parts:

A PCB (printed circuit board) - This is the "brain" of the keyboard, and it is where the switches are soldered. The PCB also contains the controller chip, diodes, and other components that make the keyboard function.

Switches - As mentioned earlier, mechanical keyboard switches are the individual mechanical switches that are used for each key. You will need enough switches to cover all the keys on your keyboard.

Keycaps - These are the plastic caps that go on top of the switches and make up the keys that you press. Keycaps come in different sizes, colors, and materials, and you can choose the ones that best suit your preferences.

Stabilizers - These are small components that help keep the larger keys (like the spacebar) from wobbling.

A case - This is the housing for your keyboard, and it can be made of plastic, metal, or wood. The case holds all the other components and protects them from damage.

A cable - This connects the keyboard to your computer. You can choose a detachable cable or a fixed cable, depending on your preferences.

In addition to these main components, you may also want to consider adding some optional extras, such as LED lighting, a plate (a thin piece of metal that goes between the switches and the PCB), or a custom-designed PCB. These features can add to the functionality and aesthetics of your keyboard, but they are not necessary for it to work.