Linux is a free and open source operating system (OS) that provides a desktop environment similar to Apple IOS or Windows. The issue with Microsoft and Apple is that they no longer provide support for older versions of their operating system, which makes many old computers obsolete IF you use their OS. However installing the correct version of Linux on these machines can bring them back to life. In simple terms, not only is the Linux equivalent to Windows XP still supported, but Linux equivalent to Windows 95 is still supported:)
While 1gb of RAM computers may or may not have a little trouble streaming videos, old computers such as this or even 512mb RAM computers can handle word processing and internet searches just fine. Now a 2gb RAM machine will be just fine for everything, meaning 10 year old computers can be perfectly adequate machines for students.
Products such as LibreOffice, which is a free open source software suite similar to Microsoft Office provide all the necessary tools for basic computer programs and these days with Google Docs and Google Sheets, all application platforms have to play nicely together.
In addition, there are a number of excellent Linux distributions that are tailored to students and the education sector such as Edubuntu, Uberstudent, and openSUSE-edu that come preinstalled with a wealth of excellent education software.