what is the difference between Retract wsp solution and remove wsp solution in sharepoint 2010

Question

what is the difference between Retract wsp solution and remove wsp solution in sharepoint 2010.

i want to remove a wsp solution from our sharepoint 2010 environment completely.

Answer 1

Retract is "uninstall this solution"

Remove is "delete the installer files"

Note that even removing a solution completely some artifacts may remain in your environment, you might need to manually remove those, things like Modules (files copied to the Content Database, like the Master Page Folder) are not usually removed unless coded that way.

Answer 2

When you install a WSP package, there's two steps:

1. Add-SPSolution (can be done only from PowerShell): this simply uploads the WSP file into the config database. Nothing really happens from the point-of-view of SP servers.
2. Install-SPSolution (can be done also from the UI): this actually tells all SP servers in the farm to get the WSP from the config and deploys its content (features, application pages, etc.) into corresponding locations (14 hive, GAC, etc...)

When you want to completely remove a package, you need to follow two opposite steps:

1. Retract the WSP package (Uninstall-SPSolution): this is where all artifacts files are actually removed from disk of all SP servers. After that, the WSP package is still in the config DB, and still visible in the UI of CA (marked as "not deployed").
2. Remove the WSP from config DB.

Note at least two caveats when retracting solutions:

1. Site collection and site features are not automatically deactivated. This means that, if you did not manually deactivated them manually before retracting the WSP, you end-up with kind of corrupted sites. Not a huge problem, but orphaned features will be flagged as such, for instance at migration time.
2. If WSP01 brings let's say a DLL, deployed into the GAC. And WSP02 also deploys the same DLL into the GAC (can be the case with a common/utils DLL): if you retract WSP02, the DLL will be removed and this will break WSP01 components!