What is update the object in workspace ?

HI

We have a standard parts which is already uploaded into windchill to the library folder .

Then I tried to upload Assembly (around 50 parts ) out of that it has one libarary part

when I checkin from workspace it isshowing "the object is already in commonspace , inorder to upload the objace in wokspace to update"

I select libary part (in workspace) ,and give update after that icon is created beside the object .

What does it meant ?

Do i need to checkin the libary part again to commonspace ?Or I can exclude the libary part ?

Note:

There is no modifcation done in that particular library part in commonspace