I will start by giving a short and simple explanation of the differences between these two. Data types in C# will either be value types or reference types. You can think of Value types as actually being the "value." All we are storing is that value. Think of Reference types as being a "reference" to the value. In this case we are storing a reference to the value you are using.

Value Type Examples

·         int

·         float

·         bool

·         byte

Reference Type Examples

·         string

·         object

·         List

·         Regex

Notice that the simpler, baser types tend to be values and the more advanced types tend to be references. If it really seems like what is being stored is just one single value, it is likely what you are dealing with is a value type. If the data seems more complex or there are simply more bits and pieces of information which are stored together, it is likely you are dealing with a reference type.

Value types are often able to be set to literal values. (42, 3.14159, true, false)

Reference types are similar to pointers in C and C++. (They are not the same, but they are close.) I say this because it helps people understand reference types to think of them as being like pointers to the data. Some C++ purists will probably criticize me for explaining it this way.

Figure 1: Basic Concept

In Figure 1, I have defined two variables: foo and bar. Notice that the value of foo is stored at the location of foo, but with bar there is only a reference to the letters.