Recompiling the Linux kernel refers to the process of building a new kernel from the source code. When you recompile the kernel, you are creating a new version of the kernel that includes any changes or modifications that you have made to the source code.
When you recompile the kernel, you do not need to recompile all of the installed applications on your system. The kernel and the applications are separate components of the operating system, and they are not directly dependent on each other.
However, if you make significant changes to the kernel, it is possible that some applications may not work properly with the new kernel. In these cases, you may need to recompile or reinstall the affected applications to ensure that they are compatible with the new kernel.
It is generally a good idea to test the new kernel thoroughly before using it in production environments, to ensure that all of the necessary applications and hardware components are working as expected.