Low vibratory energy is sometimes described as "negative" energy. High vibratory energy is referred to as "positive" energy.
For the Universe, which includes you, to be in balance and in harmony, both forms of energy are required and are necessary and appropriate in various circumstances.
Every action, every thought, every emotion creates a certain energy which you can feel. The energy may make you feel great or make you feel low. Stress is known to be a leading cause of many serious health conditions. To have optimal health one needs to reduce the stressors including those lingering in your energy field as well as within your physical body. You will feel more centered and balanced when you are energetically "clear."