It is challenging to discuss the link between meditation and relaxation because people define these terms in different ways. Some people could describe relaxation exercises as meditative, and others use meditation and relaxation as synonyms. It is important to point out that there are many different ways to meditate or to relax, and these follow a number of spiritual disciplines that could be nearly in opposition to each other.
In most forms of meditation, one key element is awareness or focus on an idea, concept, emotion, or way of being. People meditate on single words or the movement of breath, they pray, or they stay within a yoga pose and pay attention to the body. All of these are aware and highly focused on a specific thing; distractions, as much as possible, are shunted aside or encouraged to go away so focus can be maintained.
Relaxation tends not to have this type of focused awareness. For instance, imagine lying on a hammock that is swaying in the breeze. It’s comfortable, the body feels relaxed and random thoughts come and go as they please. Unless the person in the hammock is hyper aware of some aspect of self, this is not meditation. The person can feel extremely comfortable, held, warm, good, but is not focused on one thing. Meditation and relaxation aren't exactly the same in this example.
While these seem like two completely unrelated concepts, they really aren’t. It could be said that ultimately, meditation creates the hammock in the breeze. As focus exists on a single thing, the body tends to relax in other ways. Whether a person rises from the hammock or from a meditative prayer, they will feel approximately the same. Greater spiritual awareness might belong to the person who meditated, but the two people have achieved a similar state of relaxation.
Thus one link between meditation and relaxation is that they often travel to the same physical state of being. People under both states will usually have a lower heart rate, lower blood pressure, and the body may feel less constrained and tight. Both states are also linked to other benefits. They may help relieve anxiety or depression, they can have a positive effect on the way people handle stress, and they promote an overall sense of well-being that exists after they are undergone.
A question that is certainly worth asking is: why meditate when a person can just relax? Certain benefits are exclusive to meditation of different forms, including greater mental clarity, spiritual awareness, ability to find a way to get calm in unrelaxing circumstances, and possibly greater control over mental confusion or stability in difficult and easy times. While meditation may take more work than hanging out in a hammock, it appears to be worth it for those who regularly practice it. On the other hand, meditation and relaxation are both likely to confer benefits to the mind and body, and should be looked at, in their many forms, as healthful and stress-relieving.