I'm thinking about buying a Chromebook and heard that it works good with Ubuntu. My question is, what does ubuntu offer me while using a Chromebook? Does it support Arabic language?
What does Ubuntu offer me while using a Chromebook?
Ubuntu can offer everything it has to offer in general when installed in a Chromebook.
There are two popular ways of installing Ubuntu on a Chromebook known as Chrubuntu and Crouton. Only Chrubuntu uses the official version of Ubuntu. Under some conditions one can install standard Ubuntu without using either scripts. For this answer I will consider a standard stand-alone Ubuntu installation. That is, the situation where the default ChromeOS is completely replaced by Ubuntu.
Most of these will also apply for a dual boot using the Chrubuntu script.
Note: the Crouton install method uses the ChromeOS kernel and thus is not an official version of Ubuntu. This answer does not apply to Crouton.
Unlike ChromeOS, Ubuntu does not depend as much on having an Internet connection for most tasks. For example, one can write a poem or some programming codes in Ubuntu while there is no internet. To be fair, some of these things can be done without the Internet in ChromeOS as well.
If you are used to all the software that works in Ubuntu, they will work in Ubuntu installed in a Chromebook. For example, you can use Skype (if you care about Skype) in Ubuntu in a Chromebook, you can't do that with the ChromeOS.
You can use the Chrome browser in Ubuntu installed in a Chromebook. This means anything that can be done in a standard Chromebook, can be done with Ubuntu on a Chromebook.
Ubuntu won't install or work on all Chromebooks. Only Chromebooks with Intel processors work well with Ubuntu. However, some of the Intel Chromebooks don't work at all as they can't be booted into Legacy mode.
Installing Ubuntu in a Chromebook will void the warranty. And installation isn't easy. Depending on the version of Ubuntu and the make and model of the Chromebook, some parts may not work at all or not work well without further tinkering.
Chromebooks are not designed for Ubuntu. In particular, Chromebooks come with either 16GB or 32GB of internal storage. If you replace ChromeOS with Ubuntu there is enough space for a standard Ubuntu install. However, there may not be enough space for your music, video etc. in the internal storage. Replacing the internal SSD with something bigger may or may not be possible depending on the make and model. If you want to dual-boot ChromeOS and Ubuntu, you may want to buy a bigger SSD and replace the original one.
Similarly, Chromebooks come with either 2GB or 4GB of RAM. In most models the RAM is not up-gradable. So, if you want to use an app in Ubuntu that needs a lot of RAM, this will not work for you.
As far as languages go this link might be helpful
As far as installing on a Chromebook, it would probably depend on which exact one you're looking at. As far as I know they don't all share any kind of unified hardware specifications so an install may be possible on one, but not on another.