Diference between Certificates in "Login" and "System" for XCode

I try to found answer for this stupid question, but didn't find it. I am having the error CSSMERR_TP_NOT_TRUSTED and I am trying to fix it.

My question is: What difference make put a "Certificates" in "Login" or in "System" in the "KeyChains" tab of "KeyChains Access" program? Is a good idea copy and paste all certificates in this 2 places?

Say things like: Certificates in Lo开发者_StackOverflow社区gin is for use in login, and in system for system isn't the answer. :)

The System keychain is for System wide items. So if you were to have an identity for you laptop, that would be in your System keychain. Every user has access to it as well, so it's a good place for things like SSL certificates. It also takes admin credentials modify it.

On the flip side, you are the only person who can access your login keychain. It's actually locked with your account password. This is where your Apple Developer certificates should go. They are specific to you and identify a person, not a machine. Another big plus is that applications can request access to it without having admin credentials.