Good and Simple explanation on the differences of package refresh and package update in ConfigMgr and to explain you first need to understand how package distribution works.
Put very simply, when you create a package and send it to DP’s, a number of things happen:
- The package source files are compressed and sent to the DP in a PCK file
- Another file called a PKG file, containing information about the package and how the PCK files should be uncompressed, is also sent to the DP
- Once the DP has both files, it should be able to uncompress the package to the SMSPKGX$ folder
This should be used if you make any changes to the source files themselves. When you update a package, it will create a brand new, fully complete, compressed file (thats the PCK file located in the SMSPKG folder) and also create a delta compressed package file, which only has the changes made between the old and new compressed files. The delta files are then sent to all the DP’s and the new PCK file is then used for any new DP’s that are added to the package from then on. This also updates the source version of the package in SQL.
I normally use the refresh if either, I get any hash errors on clients trying to use the files to install software (the package has uncompressed but is corrupt) or in conjunction with the preloadpkgonsite.exe tool. No new PCK files are sent, it simply sends another PKG file, which then uses the current PCK file on the server and uncompresses the files again, overwriting the old package files.