Different keyboard layouts explained
QWERTY, QWERTZ, AZERTY, ANSI & ISO

The layout of a keyboard refers to the physical organization of the keys. There are many different layouts all over the world, and they vary depending on the location(country), language, and keyboard manufacturer. The most known layout is called QWERTY. It is named after the first six letters on the top row of letters.



The QWERTY keyboard layout was designed to minimize the jamming of mechanical typewriter arms during rapid typing. The concept was to position frequently consecutive letters on opposite sides of the keyboard to enable as much alternation as possible between the right and left hands while typing.

The most frequently used letters are positioned for easy access by the fingers, whereas the less common letters are situated in more challenging locations, like the positions of the letters Q and Z. The risk of jammed arms was higher if two metal arms lying next to each other got struck against the paper at (nearly) the same time. 
Because of this, the layout is designed so that letters in the same vertical row are seldom used sequentially in words. WSX is a prime example of this, as are RFV and TGB.


The metal arms of a mechanical typewriter.

Other common layouts, based on QWERTY, include QWERTZ (used in many German-speaking countries) and AZERTY (used in French-speaking countries). DVORAK is another layout that was developed to be even more efficient than QWERTY. But for several (and unknown) reasons, there is no doubt that QWERTY has gained the best foothold, and is the most widely used layout today.


The control and modifier keys on a keyboard originate from different eras. Before the age of computers, control keys served basic writing needs. Keys like [Shift], [Caps Lock], [Enter], [Space], and [Tab] were present on typewriters by the late 1800s. The advent of computers introduced navigation keys like [Home] and [End], along with additional modifier keys such as [Control] and [Alt]. While some keys, like [Scroll Lock] and [Pause], have become less useful in recent years, they remain on most QWERTY keyboards.

One of the earliest typewriters.

A 40 year old keyboard.

ANSI and ISO

Not only are there several variants of the QWERTY layout, such as QWERTZ and AZERTY, but there are also different standards that dictate specific layouts according to the language or geographical region. The most significant difference is between the ANSI and ISO standards.

ANSI
ANSI is short for American National Standards Institute and represents the most prevalent keyboard layout in North America and Australia. It utilizes the QWERTY design but features differently sized [Enter] and [Shift] keys compared to ISO. Additionally, ANSI includes a large dedicated key for the backslash.

ANSI layout, as used in the US.

ISO
ISO stands for the International Organization for Standardization. The ISO keyboard layout, also rooted in QWERTY, is predominantly used in Europe and Asia. It differs from the ANSI layout, featuring a larger [Enter] key and a smaller left [Shift] key. Additionally, a full ISO keyboard has one more key than its ANSI counterpart, totaling 105 versus 104 keys. Apart from this, there is no difference between ISO and ANSI. 


ISO layout, as used in United Kingdom (UK).


Our mechanical keyboard, Drekiskip in a 75% ISO layout.

Language variants

To accommodate the diverse requirements for letters and characters across languages, each region, country, or language typically has its own keyboard layout. As a result, variants like ISO Nordic, ISO UK, and others have been developed. While these layouts have similarly sized keys (as indicated by ISO), the placement of characters is tailored to meet specific needs. Comparing the English layout (ISO UK) with the Nordic layout, we notice that the inclusion of letters such as Æ, Ø, and Å necessitates a different arrangement for characters like brackets, colons, and symbols like the @-sign and tilde.


ISO Nordic (Norway/Denmark) layout.

Different sizes

A full-sized keyboard with an ISO layout typically has 105 keys and is considered 100% because it includes all the keys of a standard ISO layout. However, not everyone have the need for all 105 keys. Thus, there are scaled-down keyboard versions with the same layout but fewer keys. These versions are identified by the percentage of keys they contain relative to a full-sized keyboard. For instance, a keyboard with 62 keys would have 59% of the keys of a full-size keyboard, which is rounded up and designated as a 60% keyboard. An ISO layout with 83 keys constitutes 79% of a full-sized keyboard, which is then rounded to either 75% or 80%.


100% layout with 105 keys.

60% layout with 62 keys.


The term "tenkeyless" (TKL) indicates the number of keys on a keyboard. "Ten-key-less" signifies the absence of the numpad on the right side. Indeed, if one also omits the [Enter], [Num Lock], and symbol keys, 17 keys are actually missing. However, in keyboard terminology, TKL means the numpad is omitted, leaving the keyboard with 88 keys, which is about 83% of a full-size keyboard. This is often approximated to 80%.
WKL is another acronym, standing for "Winkeyless," meaning "without the Windows key." Typically, both the Windows key and the menu/function key are omitted from the keyboard's bottom row.


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