What is that one thing that we are assured of and yet scares us too? Inevitable death!!
But unfortunately we are unable to do anything about it. None of us can choose when to be born or when to die. Neither can we choose to voluntarily stay healthy despite having a hectic lifestyle. Genetics, epigenetics and finally adding our lifestyle choices in a pot will determine how we age and at which rate.
When someone utters the term "longevity," they are usually referring to all of the preceding concepts at the same time; increasing one's optimum life expectancy, increasing the average health of that person, and finally slowing down the speed of ageing. Usually, when we talk about lifespan, we don't take into consideration the fact that most of the later decades of an individual are spent in hospital beds, suffering the perils of age-related diseases. Longevity, on the other hand, talks about increasing lifespan in a way that an individual's biology is functional and youthful for a longer period of time.
Humanity has reached a tipping point in terms of lifespan, and the accompanying shifts will affect our economies, relations, vocations, and more in the next few years. However, we know this much that trying to cope with the ever-faster tempo of such developments, as well as trying to determine what or how we could incorporate such developments in our personal lives, will prove to be extremely difficult but not unachievable.