Struct:

1. It has value semantics and hence variable and value is unified.
2. Each instance can have only one owner
3. The value held by a variable can not be manipulated without changing the variable itself
4. Efficient compared to class due to copy on write and no involvement of retain count management
5. A Code that uses struct without any of its members being reference type is easy to reason because ownership is clearly defined
6. No memory leaks to deal with
7. When a variable becomes immutable, the instance also becomes immutable and if a variable is mutable then the instance also becomes mutable when it has mutable variables or mutable methods.

Classes:

1. The variable and instance are different and hence both can be manipulated separately
2. Each instance can have more than one owner
3. If an instance is amended, then all the references represented by different variables will be impacted
4. When a variable holding reference is made as immutable only the reference the variable holds is immutable not the instance the reference is pointing to. To make a class instance immutable, all its stored properties must be immutable

Thanks to KHAWER KHALIQ for providing such comprehensive writing on structs vs classes

khawerkhaliq.com/blog/swift-value-types-ref..