Meditation and mindfulness are practices that have been cultivated by people over thousands of years in many places, among various traditions, so naturally many different names have arisen for the various nuances of each of these fundamental practices.
However, we can distill all the different nuances of each practice into two simple explanations:
Meditation involves focusing attention inwards, eyes closed, and gently returning attention to an object of focus whenever distractions arise. This object of focus could be a mantra, an image, an emotion, a sensation, or the breath.
Mindfulness involves focusing attention outwards, eyes open, and gently returning attention to the senses whenever distractions arise. The five senses are sight, touch, hearing, smell, and taste.
To understand the distinction between meditation and mindfulness, you can imagine a white wall with black dots. In meditation, you isolate your attention to one particular dot to the exclusion of everything else. In mindfulness, you expand your attention to the whole wall and all the black dots.
Distractions are what interrupt our attention in either practice. Distractions are modifications of the mind. A modification of the mind is any instance where a mental impression, such as a thought or vision, arises in the mind, thereby altering it from its empty, pure, and serene natural state.
We can manage these distractions by simply allowing them to come and allowing them to go, as if they are bubbles rising from the bottom of a lake or leaves floating along the surface of a stream.
While meditation is a more formal and stationary activity scheduled at set times throughout the week, usually once or twice per day, mindfulness is a more informal and ongoing activity that can also occur throughout all daily work and recreational activities.
Choosing a particular meditation or mindfulness approach depends on any negative afflictions you may experience — anxiety, depression, or chronic pain — and any goals you may have — personal, professional, or spiritual. Upon clarification of these needs and desires, you will determine a suitable technique, find a setting, set a schedule, establish a posture, and then launch into practice.
You will experience progressive benefits as your practice deepens over time. Even within a very short period of time, you will notice benefits.