Bushcraft is the selection, use, and progression of tools, skills, and philosophy for deliberate woods living.
Survivalism is the selection, use, and progression of tools, skills, and philosophy for conditions of absolute necessity.
Very similar definitions, perhaps too much so for some. However, we see in the advancement of skills that the two categories merge together. One will choose his kit based on what he needs to deliberately live in the woods while also taking pieces of gear necessary to survive, just in case. Another will choose his kit as if there were no difference between bushcraft and survival, and the observer would not be able to tell any difference - the man would appear to only be surviving, but for the individual this is true bushcraft. For him, the very purpose of bushcraft is to become better at survival.
In truth, we are always surviving. The human is a peculiar animal who abstracts and romanticises himself, and sees living as something separate from his survival. But we are merely distancing ourselves from the realities of survival, and adding layers of complexity to what survival really is. The difference becomes clear in comparing the primitive hunter/gatherer to the modern city dweller: the hunter/gatherer has a small carrying bag, a tool and a weapon, wanders through the forest as if he is one with it, his clothes are made from the land he wanders, and he gathers or hunts the food he needs while having to endure the dangers of the animals and plants wandering with him in the forest, skill is involved in all aspects of survival, there is almost no demarcation line between what he crafts and what he endures to survive; the city dweller has an endless assortment of gear scattered throughout man-made caves/tombs that cannot even be accounted for much of the time, he carries tools but does not know that is what they are, he fears and even shuns weapons, funnels through the city as if he is the only thing in it while ironically being the same as everything else, his clothing comes from some mythical unknown place and is generally extracted from accumulated death or black oil, his food arrives in a similar manner and he generally has no clue what it looks like before it arrives in a metal or plastic can, his skills are either non-existent or crude and only apply to objects which come from the single energy source he has no idea of, and he calls this life but has no inclination of his actions threatening survival itself.
This aspect of it is part of a philosophy most won't want to touch, but it is necessary if we are to truly understand the difference between bushcraft and survival. Society and culture took a severe turn in the modern era and many people lost all connection to what the needs and realities of survival are. In other words, the rural community has traditionally been that bridge whereby humans were always in touch with the reality of survival. There was no real demarcation between daily life and survival because limited connections to the urban environment and a non-surplus of resources always left some threat which people would have to be prepared for. Much of bushcraft is simply an entertainment and academic pastime for urban dwellers, and this cultural aspect creates a much larger rift between bushcraft and survival than there actually is.
To clarify this we can add a third category, that of woodcraft. Woodcraft is the set of skills necessary for crafting wood into tools, daily living, and the living environment itself. Up until very recent history people had to care for their tools, repair them, and even build their long-term homes. An important difference here is the level of skill involved. Generally speaking, the knowledge and skill necessary to make your own tools is much higher than using them. In reality bushcraft is a focus on temporary living, the skills are employed for very basic beginnings of woods living. Much like a zombie film, just as it gets interesting, just as the group begins to survive, it ends. In this sense bushcraft is an unfinished project of woods living, just as it starts to get interesting it ends. The show Alone illustrated this well as it was a group of bushcrafters attempting to survive, and they simply did not have what it takes, not even close.
An opposite illustration comes from a story Mors Kochanski uses to illustrate his philosophy of clothing. (My version is probably way off, but the idea is the same.) An Inuit woman becomes lost out on an iceflow and is unable to make it home before dark. She has to endure the night, but for her this is easy because she is dressed for the environment and only has to wait out the night. For most people today this would be a serious survival situation, but for her it is just part of living. The art of the wilderness is contained in living and survival itself. And in many ways I think bushcraft is an attempt to get this feeling back.
It is necessary to consider how these words are defined and how they change over time, how they are imagined compared to their reality. What is survival and how has it changed as compared to ideal survival? And what is bushcraft and how has it changed compared to ideal bushcraft?