Question Need help finding the difference between 2 shaders.

Hello, I'm pretty new to shaders and graphics in general using Unity Engine.

Here is the shader I am currently using on my UI Image to blur what is in the background (frosted glass-type effect). Out of all the shaders I found on the internet, this is the only one that has worked for me. The problem is that the blur effect isn't that great, and I want to replace the blurring logic with that of another shader.

Current shader source:
https://gist.github.com/JohannesMP/7d62f282705169a2855a0aac315ff381

The new shader I want to use:
https://www.ronja-tutorials.com/post/023-postprocessing-blur/#source

Can someone please lead me to understand what's fundamentally different between these shaders? How can I modify the second one to render the same way as the first one, just being attached to a material on a UI Image and not needing to be attached to camera? Thanks!

 

first link doesn't work.