Difference between int,int16,int32,int64 C#

A number of developers think that int represents a 32-bit integer when the application is running on a 32-bit OS and it represents a 64-bit integer when the application is running on a 64-bit OS. This is absolutely wrong.
    In C# int is a primitive data type and it always mapped to System.Int32 whether the OS is 32-bit or 64-bit.
int

    It is a primitive data type defined in C#.
    It is mapped to Int32 of FCL type.
    It is a value type and represent System.Int32 struct.
    It is signed and takes 32 bits.
    It has minimum -2147483648 and maximum +2147483647 capacity.

Int16

    It is a FCL type.
    In C#, short is mapped to Int16.
    It is a value type and represent System.Int16 struct.
    It is signed and takes 16 bits.
    It has minimum -32768 and maximum +32767 capacity.

Int32

    It is a FCL type.
    In C#, int is mapped to Int32.
    It is a value type and represent System.Int32 struct.
    It is signed and takes 32 bits.
    It has minimum -2147483648 and maximum +2147483647 capacity.

Int64

    It is a FCL type.
    In C#, long is mapped to Int64.
    It is a value type and represent System.Int64 struct.
    It is signed and takes 64 bits.
    It has minimum –9,223,372,036,854,775,808 and maximum 9,223,372,036,854,775,807 capacity