Generally all sugars divide into unrefined (raw) sugars and more or less refined sugars.

Raw sugars are the only ones that are not treated with chemicals and those sugars are the most safe to use. Only some of the brown sugars are unrefined, they are called natural brown sugars and they are produced from the first crystallization of the sugar cane, for instance: demerara, muscovado (also called moscovado) and turbinado.

Unfortunately some of other brown sugars are partially refined or made of white sugar (highly refined) with addiction of cane molasses. It is done so because this way it is easier for producers to control percentage of molasses.

Brown sugars can contain different percentage of molasses, what decide about how dark they are. Molasses give sugar natural moist and soft texture, that is why molasses sugars are called “soft”.

Caster sugar can be made from both white and brown sugar crystals, it is just fine sugar that is used for baking and cooking.

White sugars are the most refined of all sugars, can be made from cane or sugar beets. Various chemicals are used to achieve white colour.

Personally I try to avoid using those highly refined white bleached sugars as much as possible because apparently there is a possibility that refined sugars are responsible for some types of cancer.

demerara

Demerara Sugar

• small raw, unrefined cane sugar crystals
• contains about 2% of molasses
• delicate flavour and aroma, perfect for coffee, cereals and cooking

turbinado

Turbinado Sugar

• light brown unrefined large cane sugar crystals
• subtle flavour, ideal for coffee, topping for cakes, ice creams, crumbles

light muscovado

Light Muscovado Sugar

• type of soft light brown unrefined cane sugar
• good for baking, cooking but also coffee or tea

Dark Muscovado Sugar

• type of soft dark brown unrefined cane sugar
• rich flavour, good for baking, cooking but also red bush tea

Molasses Sugar

• type of very dark soft brown, can be refined or not, check the labels
• very rich flavour, perfect for baking and cooking

Dark Brown Soft Cane Sugar

• type of molasses sugar, can be refined or not, check the labels
• ideal for cooking, baking and red bush tea with milk

Light Brown Soft Cane Sugar

• type of molasses sugar, can be refined or not, check the labels
• ideal for cooking, baking and red bush tea

Icing Sugar / Powdered Sugar / Confectioners’ Sugar

• ground white sugar, refined
  ideal for baking, cooking of sprinkling

White Granulated Sugar

• highly refined sugar, made from cane or sugar beets
• on most occasions can be replaced with light brown sugar

White Sugar Cubes / Sugar Lumps

• highly refined sugar, made from white sugar
• looks good on espresso saucer

Caster Sugar

• very fine white sugar, refined
• perfect for cooking, baking

Golden Caster Sugar

• very fine light brown sugar, can be refined or not, check the labels
• perfect for cooking and baking

NOTES

Please feel free to correct me if any of above information is wrong.

I will be updating this post with new information and images as soon as I will get a chance to have closer look at any other type of sugar.