Distro is short for “distribution” which, in Linux, refers to a packaged collection of software, usually including one or more desktop environments using the Linux kernel as its base. Think of a distribution as being analogous to Windows or MacOS. A distro is developed, released and maintained by a community of developers and other contributors. Some distros have commercial backing and employ people to work on them while many others are supported entirely by volunteers.
The wide variety of distributions available and actively maintained is a testament to the interest and passion of the users and community surrounding Linux and Open Source Software in general. It may seem a bit overwhelming at first but there are really only a handful of “major” distributions which the large majority of derivative or offshoot variations are based on.
The Linux distributions shown below are presented in random order. Any of these are a good option for new users. Each one is well supported, provides users with tools to manage their system and are generally very stable and easy to use. They can vary quite a bit in terms of which desktop environment they provide and other things like included software so it’s a good idea to review the options and choose at least a few to try and see which best suits your needs.