Process of applying a patch

Can someone explain to me the entire process of applying a patch, from start to finish, with all the details…

I take the example of a windows patch (office 2010 SP2 for example) that needs to be applied for the first time. So no trace in the cache files. I also suppose, to make it simple, that the windows PC is attached directly to the BigFix server, no relay.

I was able to follow the progress of a patch but I couldn’t get all the information, below are the steps I noticed:

1 - The exact patch name is displayed, for example office2010sp2.exe
2 - The patch will be downloaded, from the Microsoft or HCL site?
3 - the file is copied on the main BigFix server to the following directory \wwwwwrootbes\bfmiror\downloads\ActiveDownloads
With the name: indexed_ActionID_1

I don’t know what happens next or the things that happened that I couldn’t see.

Please clarify this process for me. I can’t find detailed documentation that describes the end-to-end patch application process in full detail. If this documentation exists, please share it with me.

Thank you in advance.