docs/mojo_and_services.md

# Intro to Mojo & Services

[TOC]

## Overview

This document contains the minimum amount of information needed for a developer
to start using Mojo effectively in Chromium, with example Mojo interface usage,
service definition and hookup, and a brief overview of the Content layer's core
services.

See other [Mojo & Services](/docs/README.md#Mojo-Services) documentation
for introductory guides, API references, and more.

## Mojo Terminology

A **message pipe** is a pair of **endpoints**. Each endpoint has a queue of
incoming messages, and writing a message at one endpoint effectively enqueues
that message on the other (**peer**) endpoint. Message pipes are thus
bidirectional.

A **mojom** file describes **interfaces**, which are strongly-typed collections
of **messages**. Each interface message is roughly analogous to a single proto
message, for developers who are familiar with Google protobufs.

Given a mojom interface and a message pipe, one of the endpoints
can be designated as a **`Remote`** and is used to *send* messages described by