Stress is the state of being under pressure. In modern usage stress refers to being under a great deal of emotional, mental or social pressure for a prolonged period of time.
A job or some other common activity can be considered stressful if it requires a greater degree of concentration for a continued period of time. A social environment or situation can also be considered stressful if there a lot of obstacles to communication or mutual tolerance.
One of the characteristics of stress is that it can give a burst of focus and awareness for a short time, but when this stressed state is prolonged, focus turns into single-mindedness and it becomes quite difficult to solve problems which require long-term vision.
There are only 24 hours in a day, and an efficient way of reducing everyday stress is re-prioritize the goals and activities of life, focus on what is truly important - and let the small stuff go.