I think a little reading is in order for you. You can see a detailed explanation of each of these types in this link:
Value Types (C# Reference)[
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Real time application of each of these types is defined by the size of the data that you are going to be placing in the variable. (i.e. If you are using a whle number between -128 and 127 then you can use an sbyte while a short will allow you a range of -32,768 to 32,767, etc.) All the information is in the link I provided.