Modifying Linux Keybindings - Background Introduction

This article provides an in-depth analysis of the three core layers of physical keyboard layouts. The first is the mechanical layout, which refers to the physical number of keys, their arrangement, and relative positions. Common standards include ANSI, ISO, and JIS; different key-count variants such as 104-key, 87-key, and Apple's compact layout all fall under this category. The second is the visual layout, referring to the characters or legends printed on the keycaps, such as letters, symbols, and Fn indicators. This part can be freely modified, and personalization can even be achieved through stickers or blank keycaps. The third is the functional layout, where the operating system or software defines the actual effect of each key, such as letter mapping schemes like QWERTY and Dvorak, as well as shortcut combinations like Ctrl+C. The article points out that while these are often collectively referred to as keyboard layouts, strictly speaking, letter arrangements and shortcuts belong to the software-level keyboard mapping. This is designed to optimize high-frequency operation paths to improve input efficiency and adapt to the needs of different regional languages and software application scenarios.