In the course of working through the
[translator example](#guide/implementing-simple-addon), we've already
encountered several of the SDK's APIs: [`request`](#module/addon-kit/request),
[`selection`](#module/addon-kit/selection), and
[`context-menu`](#module/addon-kit/context-menu).

In this section we will introduce all the modules provided in the
[`addon-kit`](#package/addon-kit) package as well as one module,
[`self`](#module/api-utils/self), which is currently in the
[`api-utils`](#package/api-utils) package but which is an important module for
add-on developers to know about.

First, though, we'll introduce some of the common idioms used throughout the
SDK.

1. [Common Idioms](#guide/api-idioms)
2. [Module Overview](#guide/api-modules)
