There are projects that require great computing power, but don’t have the funding to possess it. Some of those projects are one-person projects, sometimes created by students, other are big research projects like finding the cure for some diseases or even search for aliens 😉
BOINC is software which runs on your computer and uses your computer resources when they are not used by other programs. This makes it pleasant to use since it does not slow down your daily work. This software receives some data over the internet and then asks your computer to do some calculations. When the computer is done, it sends back the results. Millions of people use BOINC today and help humanity and science. Join us.
You can choose from various projects to contribute to. Check the list of projects on BOINC site.