Definition of an online consultation

Does anyone have a definition of what an online consultation is? Is an email to a practice for a fit note one? Is a request for an appointment one – that gets triaged into an appointment? Or only if questions are asked and answered? If I see an abnormal result and SMS a patient a message/actions about it is that one? Or does it have to be 2 way? Does allowing them to acknowledge it make it two way? Does it have to be patient initiated? Does it have to be pre-booked or can it be random? Does it have to be live or can it be asynchronous? Does a back and forth email conversation count? Does it have to be recorded in the EPR?