What's The Old Covenant?

According to WIKI...it is Gissurarsáttmáli; a covenant between Iceland and Norway.  
Were you referring to the Old Testament Covenant's?

The Old Covenant would be the Old Testament of the Bible.  It was the covenant God made with the Jewish people.  Through it the people could access God through priests who could enter the holy of holies and commune with God.  He would then take God's message to the people.  Jesus was sent to fulfill that covenant.  It was through His sacrifice that we have access to God.  It is only through Jesus that we can communicate with God.

Old covenant is covenant which God made with Israel at Mount Sinai and gave the Ten Commandments

A covenant is an agreement