You're reading the documentation for a version of ROS 2 that has reached its EOL (end-of-life), and is no longer officially supported. If you want up-to-date information, please have a look at Humble.
Options for installing ROS 2 Eloquent Elusor:
We provide ROS 2 binary packages for the following platforms:
Linux (Ubuntu Bionic(18.04))
Building from source
We support building ROS 2 from source on the following platforms:
Which install should you choose?
Installing from binary packages or from source will both result in a fully-functional and usable ROS 2 install. Differences between the options depend on what you plan to do with ROS 2.
Binary packages are for general use and provide an already-built install of ROS 2. This is great for people who want to dive in and start using ROS 2 as-is, right away.
Linux users have two options for installing binary packages:
Installing from Debian packages is the recommended method. It’s more convenient because it installs its necessary dependencies automatically. It also updates alongside regular system updates.
However, you need root access in order to install Debian packages. If you don’t have root access, the “fat” archive is the next best choice.
macOS and Windows users who choose to install from binary packages only have the “fat” archive option (Debian packages are exclusive to Ubuntu/Debian).
Building from source is meant for developers looking to alter or explicitly omit parts of ROS 2’s base. It is also recommended for platforms that don’t support binaries. Building from source also gives you the option to install the absolute latest version of ROS 2.