What is the difference between images and recipes in yocto?

Question

I am try to learn Yocto.I read the files on the website of Yocto.It is confusion that what is the difference between images and recipes?

Answer 1

A recipe is a module/program configuration (eg config for building and installing into OS our desired libraries or programs like SSH services or nano editor). Image - is a resulting OS image ready for deployment onto eg USV stick or NAND.

Answer 2

Recipe - All software/library should be described for Yocto Project via bitbake to process it: Download, decompress, patch if necessary, compile, and package (.deb, .ipk, .rpm)

Image - Includes all the recipes you want to install, example (openssh, picocom, python3, ...) in addition to being able to automate the image with Hostname, configured IP, startup scripts. The image would already be the end result of Bootloader + Kernel + Rootfs (your installed applications and programs). In addition to many other customizations for the OS at startup, different File Systems and etc.

Answer 3

Recipes are the most common file type in a Yocto build description. They contain instructions on how to configure, compile and deploy a given piece of software. Recipes also contain the location of the source code. This location can either be a static release archive, or a reference to a Git repository. Custom modifications to the sources themselves or the build process can be provided in form of patches. To minimize repetition for common tasks in recipes, such behavior is encapsulated in recipe class files, from which recipes can inherit.

Image contains all packages which have to be built and installed into the final root file system. The build system will take care that any known dependent package will also be installed. The end goal for anyone using the Yocto Project should be to create a Linux distributions that is customized to match your product(s) requirements. Images are a central concept within the Yocto Project and essential to the definition of a Linux distribution.