In meditation, the same words appear across traditions, often used loosely and interchangeably. Even I am guilty of this. So let's define these terms at the outset for functional purposes: attention, intention, awareness, mindfulness, consciousness.
Attention
Attention is a localization of perception. Let's say there's an abrupt sound, a car, or a dog starts barking. That aspect of the mind which attends to that sound, which is captured by that sound, is attention. I can place my attention on this object, I can place my attention on that object. It is really the localization of perception.
Perception, in Buddhism, means two things. It means the act of receiving sense data on a given object, and it means the recognition that comes from memory. In order to recognize a cup as a cup, there has to be the receiving of that sense data, and then there has to be the recollection of what a cup is. Perception and memory are considered the same aggregate. If the incoming sense data is there but the memory isn't, there's an argument to be made that you wouldn't perceive the object at all.
Intention
Intention is the application of any particular function in experience. If attention is the localization of perception, intention is what exercises the shifting of that attention when it's voluntary. For me to move my hand from here to here requires the exercising of intention. It is that driver behind a movement.
Most of our attention, how it moves, what it's engaged in, what it does, is involuntary. The meditative process is attempting to break that involuntary patterning of attention. An Instagram ad comes up, it captures your attention involuntarily, and then this whole chain of processing happens after that. A great deal of our desires and responses are conditioned in exactly the same way.
Awareness
In non-duality and in meditation language, awareness is often used as another word for consciousness, which creates confusion. In the general sense, awareness just means noticing something. But what we mean in meditation by the presence of awareness is that the faculty of being aware and being conscious turns on, or is present. Usually it's not present. Usually we're on autopilot.
This presence of awareness will last about thirty seconds, or maybe a minute, and then you're back on autopilot. Your mind really only has two modes: you're aware, or there's no awareness.
When you're in a dream and you recognize that you're dreaming, that noticing breaks the ordinary dream and turns it into a lucid dream. The dawning of the recognition that you're in a dream is what turns it lucid. The visceral presence of awareness in meditation is similar, the mind becoming conscious for a few seconds or a few minutes, depending on what your capacity is for this.
Consciousness
What is the difference between awareness and consciousness? Consciousness is uninterrupted and continuous. You've never had an experience outside consciousness. You've never known consciousness outside consciousness. Consciousness, reality, experience: three words for the same thing.
When you fall asleep, you lose consciousness, and when you wake up, consciousness turns on. That which turns on first thing in the morning and turns off last thing in the evening: that's consciousness. And it's present through the entirety of the day. Actually, it's even present when you're sleeping, but it takes clear light yoga and samadhi to realize that.
Mindfulness
Mindfulness is when awareness, that being conscious, is directed at an object. Mindfulness of the body, mindfulness of breathing, mindfulness of feeling. It just means that that fullness of mind, that presence of awareness, is directed at something.
Awareness is a noun. Mindfulness is a verb. Awareness refers to that faculty or mode itself. Mindfulness is the moment-to-moment knowing of an object. "My mindfulness was broken" means the continuity of attending to something was interrupted. You wouldn't refer to awareness the same way.
When mindfulness is directed at an object, the enlightenment factors automatically begin to build, like a program. As soon as you set the program, this whole mechanism begins to unfold on its own.
The Right Approach
The approach to meditation that is most effective and accessible emphasizes letting go, non-doing, a total resting, allowing things to be what they are.
I spent seven years trying it the other way. I spent seven years doing various concentration practices without the necessary conditions. There's a real pain in attempting to attain the things you think you're supposed to attain outside of the right conditions. The frame needs to be that your meditation practice is just getting out of the way. Allowing things to be exactly as they are. The less that you're doing, the less that you're involved, the more that your true mind will be recognized. You want to arrive at the truth that this process is doing itself.
It's really the attempt to control and the attempt to fabricate, I want it to be this way, I'm going to be upset if it's not this way, that is the crux of not only suffering but is what actually bars a person from entering deeper levels of samadhi or falling into cessation.
The Ocean
Meditation is like an ocean. The conceptual thinking mind, where analysis and investigation and meaning is occurring, is at the surface, where the waves are quite noticeable and intense. That's where most of us live most of the time. I need to do this, I need to do that, remembering this, planning that, executing. Quite a bit of turbulence.
Straight down into the depths, the water becomes still. At the bottom of the ocean, the water is completely still. It's only turbulent at the surface.
When you allow the technique to do itself, when you get out of the way, when you stop attempting to control, when you let go, when you allow things to be exactly as they are, the enlightenment factors, equanimity, tranquility, all of these begin to mature as the sinking down into the depths occurs. The nervous system calms down, the body calms down.
It's already the case that you're the bottom of the ocean. It's already the case that this deep stillness is there, that this more fundamental awareness is the case. It is there. But because our attention is always at the surface and because we haven't given it sufficient time, we never sink to the bottom and experience deeper silence, deeper stillness.
The Water Bottle
Imagine a water bottle full of sediment, full of dirt and sand. Shake it up and you can't see through the water. Now just set the water bottle down. Don't do anything. Just leave it. If you move it, it disturbs the sand. But if you just set it down and leave it, the sediment eventually settles and you can see the clarity of the water right through the bottle.
That is exactly what we're doing with jhana. You set the conditions right, approach the meditation object correctly, set it down, do nothing.
Each jhana, as you progress through them, you're becoming calmer and calmer and calmer. More released, more let go, deeper into the depths of that ocean. The non-doing and the non-action reach a culmination. And that culmination is falling out of oneself completely.