electron/docs/glossary.md

Glossary

This page defines some terminology that is commonly used in Electron development.

ASAR

ASAR stands for Atom Shell Archive Format. An asar archive is a simple tar-like format that concatenates files into a single file. Electron can read arbitrary files from it without unpacking the whole file.

The ASAR format was created primarily to improve performance on Windows... TODO

Brightray

Brightray is a static library that makes libchromiumcontent easier to use in applications. It was created specifically for Electron, but can be used to enable Chromium's renderer in native apps that are not based on Electron.

Brightray is a low-level dependency of Electron that does not concern the majority of Electron users.

DMG

An Apple Disk Image is a packaging format used by macOS. DMG files are commonly used for distributing application "installers". electron-builder supports dmg as a build target.

IPC

IPC stands for Inter-Process Communication. Electron uses IPC to send serialized JSON messages between the main and renderer processes.

libchromiumcontent

A single, shared library that includes the Chromium Content module and all its dependencies (e.g., Blink, V8, etc.).

main process

The main process, commonly a file named main.js, is the entry point to every Electron app. It controls the life of the app, from open to close. It also manages native elements such as the Menu, Menu Bar, Dock, Tray, etc. The main process is responsible for creating each new renderer process in the app. The full Node API is built in.

Every app's main process file is specified in the main property in package.json. This is how electron . knows what file to execute at startup.

See also: process, renderer process

MAS

Acronym for Apple's Mac App Store. For details on submitting your app to the MAS, see the Mac App Store Submission Guide.

native modules

Native modules (also called addons in Node.js) are modules written in C or C++ that can be loaded into Node.js or Electron using the require() function, and used just as if they were an ordinary Node.js module. They are used primarily to provide an interface between JavaScript running in Node.js and C/C++ libraries.

Native Node modules are supported by Electron, but since Electron is very likely to use a different V8 version from the Node binary installed in your system, you have to manually specify the location of Electron’s headers when building native modules.

See also Using Native Node Modules.

NSIS

Nullsoft Scriptable Install System is a script-driven Installer authoring tool for Microsoft Windows. It is released under a combination of free software licenses, and is a widely-used alternative to commercial proprietary products like InstallShield. electron-builder supports NSIS as a build target.

process

A process is an instance of a computer program that is being executed. Electron apps that make use of the main and one or many renderer process are actually running several programs simultaneously.

In Node.js and Electron, each running process has a process object. This object is a global that provides information about, and control over, the current process. As a global, it is always available to applications without using require().

See also: main process, renderer process

renderer process

The renderer process is a browser window in your app. Unlike the main process, there can be multiple of these and each is run in a separate process. They can also be hidden.

In normal browsers, web pages usually run in a sandboxed environment and are not allowed access to native resources. Electron users, however, have the power to use Node.js APIs in web pages allowing lower level operating system interactions.

See also: process, main process

Squirrel

Squirrel is an open-source framework that enables Electron apps to update automatically as new versions are released. See the autoUpdater API for info about getting started with Squirrel.

userland

This term originated in the Unix community, where "userland" or "userspace" referred to programs that run outside of the operating system kernel. More recently, the term has been popularized in the Node and npm community to distinguish between the features available in "Node core" versus packages published to the npm registry by the much larger "user" community.

Like Node, Electron is focused on having a small set of APIs that provide all the necessary primitives for developing multi-platform desktop applications. This design philosophy allows Electron to remain a flexible tool without being overly prescriptive about how it should be used. Userland enables users to create and share tools that provide additional functionality on top of what is available in "core".

V8

V8 is Google's open source JavaScript engine. It is written in C++ and is used in Google Chrome, the open source browser from Google. V8 can run standalone, or can be embedded into any C++ application.

webview

webview tags are used to embed 'guest' content (such as external web pages) in your Electron app. They are similar to iframes, but differ in that each webview runs in a separate process. It doesn't have the same permissions as your web page and all interactions between your app and embedded content will be asynchronous. This keeps your app safe from the embedded content.