Difference between support packages, kernels & SAP Note

Snote :-

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By implementing an SAP Note an error in a single program or 
Transaction is removed.
You can apply these using SNOTE

Support Package:-

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Applying an SAP Support Package, all errors are corrected that
Were known, SAP Support Package is nothing but bunch of corrections.
(Collection of corrections of serious errors in the ABAP/4 Repository)
You can apply this using transaction SPAM
 Kernel :-

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SAP Kernel is the core of the application. Like all other applications the Kernel contains the executable files (.EXE files for stating various processes in SAP.
That’s the reason when a Kernel upgrade is done it means new versions of the various EXE files replace the older versions.
 With regards to advantages, it is an appropriate question in this context since the Kernel is a must (.EXE)