I got this simple explanation from the CTO (Chief Technology Officer - the most important technical person in the company). He then asked me (I was the project manager), to set milestones and supply a timetable.
I was a rookie in the industry straight out of the university. I had the privilege of managing a project because I was part of a startup. At startups there are a lot of opportunities because startups must manage with what they have.
Anyway, milestones are applicable in various domains that have long continuous processes. Milestones help us track progress. For example when a baby grows and develops, in order to quantify his development we have milestones such as "the first time the baby turns over" or "the first steps".
At these points we can say "oh.. he's developing!" and we note them.
Professional development has its own milestones. Some of them are obvious like finishing the first year at university, getting the bachelors degree, masters, PhD, the first day at work, etc. Some milestones are hidden, like the first time selling a big idea to a colleague/manager or the first time looking for a new job in stealth.
Several weeks ago I celebrated some of my own milestones.
I had my first business trip where I presented (in front of an international audience) a paper of which I was the main author. I conducted conversations with other researchers, fluently, with confidence as an expert in my field.
That was a really exciting experience.
(below - me presenting, the place and the audience)
