An experience may be conscious or unconscious i.e. reactive behaviour where as a realisation allows knowledge or insight into how consciousness works for all humanity generally and cannot be contradicted by time and circumstance. Two examples of a realisation are
(i) change is changeless
(ii) movement is proof of limits
and whilst an individual may include this awareness in their life they will not have any ability to alter that awareness as it is common to all humanity.
A personal experience such as that which comes in meditation or in our day-to-day living may have a personal interpretation placed upon it and we then form our own personal bias to suit our own agenda.
In summary, a realisation is something which is universal to all humanity and an experience is personal.