When people think of stress, they usually think of it as a bad thing, certainly not good thing, but stress can actually be beneficial. Stress is classified into three types: Eustress, Neustress and Distress. They differ on how they affect a person or individual. Let's tackle them one by one.
Eustress is the good kind of stress. It is stress that gives motivation and inspiration. This stress arises from many situations. For example, being promoted or winning a new job gives a person a bit of stress in the sense that they will have to adjust to new working conditions as well as create new relationships with new co-workers together with job performance expectations. It is, however, a good stress in that it gives you motivation to do your job well and the promotion or job offer itself serves as a reward or a prize for the hard work you have done.
The second type of stress is distress. It is basically the complete opposite of Eustress in terms of its effect on an individual. This type of stress causes ill effects to a person and is what people usually refer to when talking about stress. If someone is talking about stress it is almost always concerned with negative distress. Distress causes despair, grief, and sadness or more simply it disturbs the equilibrium of the body. An example of a stressor that can cause distress is the death of a spouse, major medical difficulties or some major loss of property or position. At its worst it will certainly cause grief and depression and will often be a life changing event.
The last type of stressor is called neustress. Neustress comes from the prefix 'neu' meaning neutral and is basically a type of stress that lies in the neutral reaction zone. It is a stress that doesn't cause any particular harm or grief to the individual to the extent that it causes distress. Nor is it necessarily positive or a motivating change stress. Here's an example - when someone happens to overhear a conversation at a store while they are shopping. That person may be talking about their son's sickness or misfortune or even death with their friend. How do you think that situation will affect the person who just overheard the conversation? Well, a person may react to it and show sympathy to the one concerned but it will only last moments and it will not affect the person in a either a negative or in a positive way, certainly not in the same way or to the same extent that knowing the person concerned would affect them and therefore it is considered a neutral impact. Simply put, think of it as a judge hearing out a case of murder, the judge doesn't take sides but only views the facts and decide what's right and just.
The ultimate impact though of the types of stress you are experiencing comes down to how you perceive or see the stressor, in light of your own opinions and world view. What hardly affects one person at all but have a great impact on another. Whether you take an event as good, bad or neutral is... well... at the end of the day... up to you.