expired certificate
Hello, I have had the attached message in Keychain for some time now.
Is it important?
HOw do I renew the certificate?
Also as a general enquiry, there does not seem to be a general explanation of terms like "public key", "application password" , "network password", "handoff encryption key" etc. There are thousands of "public keys" on my machine and I am tempted to delete them. Should I? Is there a general blurb on the net that explains the guts of keychain?
MacBook Pro 15", macOS 10.15