Following are the main points of difference between classes and structs in C#:

1. Structs are value type and classes are reference type.
• Whenever a struct object is assigned to another struct object a copy is created. In case of classes the same operation results in two references referring to same object: For example, a.x = 10; b = a; a.x = 20; cout << b.x will display '10' if a and b are struct objects and it will display '20' if a and b are class objects.
• Boxing of a struct object creates a copy of the object in a different type, whereas, boxing a class object creates a reference (of different type) to the same object.
2. Inheritance is

Following are the main points of difference between classes and structs in C#:

1. Value type vs Reference type: Structs are value type and classes are reference type.
   • Whenever a struct object is assigned to another struct object a copy is created. In case of classes the same operation results in two references referring to same object: For example, a.x = 10; b = a; a.x = 20; cout << b.x will display '10' if a and b are struct objects and it will display '20' if a and b are class objects.
   • Boxing of a struct object creates a copy of the object in a different type, whereas, boxing a class object creates a reference (of different type) to the same object.
   • Since structs are value type it is not possible to assign null to a struct object.
   • When a struct object is passed to a function as a parameter it is passed by value, unless specifically marked as 'ref' or 'out' parameter.
2. Inheritance: Inheritance is not allowed for structs.
• All struct types implicitly inherit from System.ValueType and they are implicitly sealed.
• The keywords related to inheritance concepts are not allowed for structs. For example, abstract, protected, virtual, override etc.
3. Initialization: Structs cannot have default constructor.
• All struct member variables of value type are initialized to their default values and reference member variables are initialized to null.
• Field initializers (initialization in the member variable declaration line like int a = 0; ) is also not allowed for structs.
4. Destructor: Structs cannot declare a destructor.
5. Meaning of 'this':
• For a struct instance constructor (parameterized) 'this' is treated as an out parameter.
• For other member functions it is treated as a 'ref' parameter.
• So it is possible to assign to 'this' and change the current object.
• In case of a class 'this' is considered as a value, so it is not possible to assign to 'this' from inside a class.
• Since 'this' is a 'ref' or 'out' parameter, it must be definitely assigned at every point where it is used.