Difference between Constant and Read only

Difference between Constant and Read only :

• The read only keyword differs from the const keyword. 
• A const field can only be initialized at the declaration of the field. 
• A readonly field can be initialized either at the declaration or in a constructor. Therefore, readonly fields can have different values depending on the constructor used. 
• Also, although a const field is a compile-time constant, the readonly field can be used for run-time constants,as in this line: public static readonly uint l1 = (uint)DateTime.Now.Ticks;