what is the difference between custom workflow and system workflow?

So many developers say's many differences with my knowledge i'm sharing few oh the differences which are as follows:

System Workflow :

--> It is out of box feature(OOB) which follows the predefined steps for development.

Custom Workflow :

-->It is the code based file which helps us to implement which is not possible from OOB feature of the system workflow.This code base file should be a DLL(Dynamic-link library) file which should be called from the out of the box workflow designer.

-->From custom workflow we can have the operations such as CRUD,Associate,Disassociate,Execute.where we can develop according to requirement