SWEAR, CURSE, and PROFANITY
Swear is what we do when we go to court to participate in a case. We take an oath, or swear to tell the truth. If you watch Judge Judy or other such programs you will hear the bailiff say "The litigants have been sworn in, your honor." Or the bailiff may say "All litigants please raise your right hand. Do you promise to tell the truth in these matters?"
And when we get married we take an oath to be faithful till death do us part.
Notice that no profanity or obscenity is involved and the name of the Lord is not taken in vain.
To curse is to call on the powers beyond our control to bring evil on another person. For instance, I may say "By the hair on my chinny-chin-chin and the cheese under my toe nails, may your teeth become infested with scum and rot out."
Notice that no profanity is involved and the name of the Lord is not taken in vain.
PROFANITY OR OBSCENITY OR VULGARITY
Profanity or obscenity or vulgarity is characterized by the use of certain 'four-letter' words.
Notice that the name of the Lord is not taken in vain.
THE THIRD COMMANDMENT"Do not swear falsely by the name of the LORD..."
This commandment is to never use the name of God in a vain, pointless or insincere oath. Notice that no vulgarity need be involved.