there are several different but fundamental turns;can you explain the
mechanics of the swivel turn and the spot turn...I conceptualize this enough

Roxsinger. The question i take it is on Latin. According to the International style a Spot Turn is a Walk Turning over the Walking Foot. The turn is done over the foot that has stepped with the whole of the foot on the floor. In other words you have fully commited your weight onto that foot and turned. From the book. Spot Turn to the Right.
Left foot across body turning to finish LF slightly to side.
RF in place. ( Turn the toe out, or rather turn the heel in )
Left foot to side. One turn to the right completed.
Swivels in Latin . In the Argentine Tango there are multitudes of Swivels
Step and bring the moving foot to the standing foot flat on the floor without weight. Using the same moving foot to step in your new direction. These can be done backwards and forward.
I need to put this in. Some dancers are doing the Spot Turn in the Rumba with a swivell. And the normal Spot Turn is named a Switch Turn. So if you have seen something where the RF has moved to the LF and then moved out. You haven' t been seeing double. Its perfectly legal. But not in the book. I hope this is what you were after.

nd straight legs between steps 1 & 2.

On the now accepted Spot Turn the moving foot is brought to the standing foot. Whenever the feet close there is always a high instep which meens the knee must bend and then become straight as it is placed on the count of three. Dont forget which ever one you do turn the toe out on three.