Structs and classes are both user-defined data types in C#. However, there are some key differences between the two.

• Value type vs. reference type: A struct is a value type, while a class is a reference type. This means that when a struct is assigned to a variable, the variable will contain the actual value of the struct, not a reference to the struct. For example, if you have two variables, a and b, and you assign the value of a to b, b will contain the same value as a, not a reference to a.
• Size: Structs are always the same size, regardless of the number of fields they contain. Classes, on the other hand, can be any size, depending on the number and size of their fields.
• Encapsulation: Structs and classes can both be encapsulated, meaning that their fields can be declared as private, protected, or public. However, structs cannot have a default constructor, while classes can.
• Inheritance: Structs cannot inherit from other structs or classes, while classes can inherit from other classes.
• Operator overloading: Structs and classes can both have operators overloaded, but the rules for doing so are different.

In general, structs should be used for data types that are small and simple, such as Point or Color. Classes should be used for data types that are complex or that need to be inherited from, such as Person or Customer.

Here is a table that summarizes the key differences between structs and classes in C#:

Class and struct are both user-defined data types, but have some major differences.

Struct

1. The struct is a value type in C# and it inherits from System.Value Type.
2. Struct is usually used for smaller amounts of data.
3. Struct can’t be inherited from other types.
4. A structure can't be abstract.
5. No need to create an object with a new keyword.
6. Do not have permission to create any default constructor.

Class

1. The class is a reference type in C# and it inherits from the System.Object Type.
2. Classes are usually used for large amounts of data.
3. Classes can be inherited from other classes.
4. A class can be an abstract type.
5. We can create a default constructor.