Information about Linux, and what you can expect as a recipient of a laptop
Linux is a free operating system.
Most laptops in the REcompute program come installed with Linux Mint. https://linuxmint.com/about.php. It is a simple but very powerful operating system, and comes preloaded with lots of useful software, such as LibreOffice, an office suite which will open and save documents compatible with MS Office, as well as Firefox for web browsing, Thunderbird Mail for email, and much more.
If you have any experience with computers (Windows or Mac) you will find the Linux Mint version installed by REcompute to be very familiar and intuitive. REcompute recipients with no computer experience have found this version to be very easy to use.
If the laptop you have received is an older one, with, for example, less RAM, it might have installed on it a different Linux 'distro' (distribution) better suited to make the best of its specifications.
Examples of other Linux distros might be