Fruits are parts of plants that contain seeds (apples, tomatoes, cucumbers, peepers, okra, lemons). What people consider ripe fruit is not always related to the botanical ripeness (the seeds are mature and ready to be dispersed)
Vegetables are all the other parts of plants that we eat
Vegetables do not ripen, they just grow. Many plants are better tasting and more edible at certain times in their growth cycle, but this is generally based on your culture and preference, there are no firm rules. Very few plants change from being poisonous to be edible during their growth cycle
All fruits and vegetables begin to decay the day they are harvested. In some fruits this is to their taste advantage, in most vegetables this is not. Fruits that are picked before they are ripe may improve in flavour and texture over a few days of suitable storage
In most cases fruit and vegetable nutritional profiles decay from the day they are harvested