Liquid sugar vs simple syrup?

What is simple syrup ... and what do you do with it?

Types of Simple Syrups:

There are several thicknesses or densities of simple syrup and they have different uses. The thickness depending on the ratio of water to sugar used. The one with more sugar will be more syrupy and sweeter. Follow the measurements listed in your recipe, or use these general guidelines:

Thin Simple Syrup - A ratio of 3 parts water to 1 part sugar - used to glaze cakes and cookies.

Medium Simple Syrup - A ratio of 2 parts water to 1 part sugar - used to make sweeten beverages and iced tea.

Thick or Rich Simple Syrup (basic simple syrup) - A ratio of 1 part water to 1 part sugar - This is used as the basis for cold fruit drinks and cocktails. Also used to make candied fruits. Bartenders usually prefer this simple syrup for cocktails.

It is the same thing and yes that's a preservative. I use it or crushed vitamin C in guacamole to keep it from turning brown. Fruit fresh might be the same thing also if I remember correctly.

Does it not need refrigeration? I've run into a few recipes for it and I just use boiling water (least amount possible to still dissolve sugar) and then ice cubes.

The reason for it is that if you have a cold beverage like tea and lemonade not everyone likes it sweet enough to rot your teeth. LOL and sugar does not dissolve well in cold liquid. In a restaurant my husband will use artificial sweetener as it does dissolve.