The end result of a legal separation is what is different. The procedure is the same. The end result in a legal separation case is that the parties remain married. In a divorce, obviously, the end result is that the parties are divorced.
Sometimes, people will chose a legal separation over a divorce because they want to remain on someone’s health insurance or they choose to do it this way for religious reasons.
Upon a legal separation being finalized, in the future, if the parties wish to marry someone else, they will not be permitted to do so unless they go back to court to terminate the earlier marriage through divorce or dissolution.