Two temperatures for making caramel candy
When caramelizing sugar in a recipe that uses water your first job is to get the sugar to completely dissolve. That is the first temperature you are using. They are probably making you pause at this temperature long enough to make sure you do this tep correctly. If they didn't have the step most folks would blow past it, add more ingredients and run the risk of not dissolving the sugar correctly.

Make sure no sugar crystals remains at the first stage, even on the side of the pot. If any crystals remain or fall in later your recipe will fail because the sugar will recrystallize leaving a grainy taste.