How is retrieval related forgetting different from forgetting due to interference?

Forgetting due to retrieval failure:

Forgetting can occur because at the time of recall, either the retrieval cues are absent or they are inappropriate. Retrieval cues are aids which help us in recovering information stored in the memory. This view was advanced by Tulving and his associates who carried out several experiments to show that contents of memory may become inaccessible either due to absence or inappropriateness of retrieval cues that are available/employed at the time of recall.

Forgetting due to interference: It suggests that forgetting is due to interference between various informations the memory store contains. According to this theory learning and memorising involve forming of associations between items and once acquired, these associations remain in fact in the memory. People keep acquiring numerous such associations and each of these rests independently without any mutual conflict. However, interference comes about at a time of retrieval when these various sets of associations compete with each other for retrieval.