what does reset my default keychain do?

Thank you. Obviously I won’t be doing that accept as a last resort. I was having a problem… I downloaded a certificate from my developer account and when I double clicked on it nothing changed in My Certificates or Certificates. Keychain Access was open. But next time I closed Keychain Access and opened it (this was after the message I posted here… when it did not show up immediately the first time I was concerned and started looking for reasons why. Some people suggested a corrupt keychain and the reset keychain solution) anyway, next time I closed and reopened

my keychain a new certificate appeared. However it was a duplicate of one I already had in the keychain… just the expiry date changed. Here’s the thing, in my developer account on Apple it’s called “Mac Development” and in my keychain the same certificate, expiring exactly one year from today, is called “3rd Party Mac Developer Application”. What? How are we (developers) supposed to be able to relate these two things? It drives me nuts. There is no systematic naming between certificates on your device and certificates in your Apple developer account. And you have multiple certificates all claiming to do the same thing (why?). How is one supposed to know which is appropriate for what? Like I said, it’s just a mess and it drives me nuts. If you have any influence please make this aspect of developer responsibilities crystal clear: create a single name that describes a certificate and use that name everywhere, and don’t create multiple certificates to do the same job. Cheers!!! And thanks again for clearing up what the reset keychain function does. Hopefully there are plenty of warnings when that option is selected.