Raspberry Pi OS
Your Raspberry Pi needs an operating system to work. This is it. Raspberry Pi OS (previously called Raspbian) is our official supported operating system.
Install Raspberry Pi OS using Raspberry Pi Imager
Raspberry Pi Imager is the quick and easy way to install Raspberry Pi OS and other operating systems to a microSD card, ready to use with your Raspberry Pi.
Download and install Raspberry Pi Imager to a computer with an SD card reader. Put the SD card you'll use with your Raspberry Pi into the reader and run Raspberry Pi Imager.
To install on Raspberry Pi OS, typesudo apt install rpi-imager
in a Terminal window.

Manually install an operating system image
Browse a range of operating systems provided by Raspberry Pi, and download them to install manually.
See all download optionsRaspberry Pi Desktop for PC and Mac
Debian with Raspberry Pi Desktop is our operating system for PC and Mac. It provides the Raspberry Pi OS desktop, as well as most of the recommended software that comes with Raspberry Pi OS, for any PC or Apple Mac computer.
Download Raspberry Pi Desktop