# 3.1 Modifier Layers A modifier layer is activated when a key is held and one or more key code modifiers like shift, control, option, alt, altGr, command, windows gui and/or super key are applied. New key codes can then be defined using a modifier + a default layer key, creating a modifier layer. Many applications can also detect the difference between a left and right modifier. That creates many more modifiers depending on your OS available modifiers. Because many applications will use 1 or 2 modifiers for shortcuts, often modifier layers use 3 or more modifiers. The two most popular have a name like the **Meh key** which is the left control, (alt/option), shift and the **Hyper Key** which is left control, (alt/option), shift (command/windows). Modifier layers are a great entry point for layers because they can be done with only software. My first layer used [auto hotkeys](https://jonny-wamsley.gitbook.io/the-ultimate-guide-to-keyboard-layers/ch-2-setup/2.3-software) that modified the left alt key into a hyper key. This allowed me to create a navigation layer by then redefining hyper j, i, k, l keys into arrow keys. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://jonny-wamsley.gitbook.io/the-ultimate-guide-to-keyboard-layers/ch-3-layer-activators/3.1-modifier-layers.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.