What is the difference between synchronized swimming and synchronised swimming?

"Normal" swimming is usually considered to be individual lap swimming or individual or relay competition and is one of the four racing strokes: Front crawl(or freestyle), butterfly, breastroke, or backstroke. Each of these can be perfected by preset standards. Another "normal" stroke may be elementary backstroke but it is a resting stroke and not in any competition.

Synchronized swimming consists of a team that works together to invent a routine based on the standard moves.