What is the difference between "upgradesolution" and "retractsolution, deletesolution, addsolution & deploysolution"? is it both of them working in a similar way?

Hi,UpgradesolutionUpgrades an existing solution. The solution to be upgraded could be either deployed or not deployedRetractsolution, deletesolution Retracts the specified solution’s deployment. The retractsolution operation removes files from the front-end Web server. The deletesolution operation deletes the solution package in the solution store of the configuration, and should only be called after solution packages have been retractedAddsolutionAdds a solution file to the solution storeDeploysolutionDeploys files related to a solution from the configuration database to individual front-end Web servers in the farmdetails is here http://technet.microsoft.com/en-us/library/cc263231.aspxBest Regards, Ammar MCT http://ahmed-ammar.blogspot.com Posting is provided "AS IS" with no warranties, and confers no rights.

actually, I want to know that whether we can use the set of "retractsolution, deletesolution, addsolution & deploysolution" commands instead of "upgradesolution" command, will both of them accomplish the same job?lets say,I've a solution package deployed.It throws some-error, while trying to upgrade the solution package.so, will be able to use the set of "retractsolution, deletesolution, addsolution & deploysolution" commands to install the upgraded solution package. if so, will both of them are treated in a similar way?

According to http://msdn.microsoft.com/en-us/library/aa543659.aspx , solution upgrade can only be used to replace files. You can add new files in a solution upgrade and remove old versions of the files, but you cannot install Features or use Feature event handlers to run code for Feature installation and activation. You won’t have such kind of limitation with the set of "retractsolution, deletesolution, addsolution & deploysolution" commands.