Five Skandhas

https://www.learnreligions.com/the-skandhas-450192

(Emphasis is mine)

The First Skandha: Form (Rupa)

Rupa is form or matter; something material that can be sensed. In early Buddhist literature, rupa includes the Four Great Elements (solidity, fluidity, heat, and motion) and their derivatives. These derivatives are the first five faculties listed above (eye, ear, nose, tongue, body) and the first five corresponding objects (visible form, sound, odor, taste, tangible things).

Another way to understand rupa is to think of it as something that resists the probing of the senses. For example, an object has a form if it blocks your vision -- you can't see what's on the other side of it -- or if it blocks your hand from occupying its space.

The Second Skandha: Sensation (Vedana)

Vedana is a physical or mental sensation that we experience through contact of the six faculties with the external world. In other words, it is the sensation experienced through the contact of eye with visible form, the ear with sound, nose with odor, tongue with taste, body with tangible things, mind (manas) with ideas or thoughts.

It is particularly important to understand that manas -- mind or intellect -- is a sense organ or faculty, just like an eye or an ear. We tend to think that mind is something like a spirit or soul, but that concept is very out of place in Buddhism.

Because vedana is the experience of pleasure or pain, it conditions craving, either to acquire something pleasurable or avoid something painful.

The Third Skandha: Perception (Samjna, or in Pali, Sanna)

Samjna is the faculty that recognizes. Most of what we call thinking fits into the aggregate of samjna.

The word "samjna" means "knowledge that puts together." It is the capacity to conceptualize and recognize things by associating them with other things. For example, we recognize shoes as shoes because we associate them with our previous experience with shoes.

When we see something for the first time, we invariably flip through our mental index cards to find categories we can associate with the new object. It's a "some kind of tool with a red handle," for example, putting the new thing in the categories "tool" and "red."

Or, we might associate an object with its context. We recognize an apparatus as an exercise machine because we see it at the gym.

The Fourth Skandha: Mental Formation (Samskara, or in Pali, Sankhara)

All volitional actions, good and bad, are included in the aggregate of mental formations, or samskara. How are actions "mental" formations?

Remember the first lines of the Dhammapada (Acharya Buddharakkhita translation):

Mind precedes all mental states. Mind is their chief; they are all mind-wrought. If with an impure mind a person speaks or acts suffering follows him like the wheel that follows the foot of the ox.
Mind precedes all mental states. Mind is their chief; they are all mind-wrought. If with a pure mind a person speaks or acts happiness follows him like his never-departing shadow.

The aggregate of mental formations is associated with karma because volitional acts create karma. Samskara also contains latent karma that conditions our attitudes and predilections. Biases and prejudices belong to this skandha, as do interests and attractions.

The Fifth Skandha: Consciousness (Vijnana, or in Pali, Vinnana)

Vijnana is a reaction that has one of the six faculties as its basis and one of the six corresponding phenomena as its object.

For example, aural consciousness -- hearing -- has the ear as its basis and a sound as its object. Mental consciousness has the mind (manas) as its basis and an idea or thought as its object.

It is important to understand that this awareness or consciousness depends on the other skandhas and does not exist independently from them. It is awareness but not a recognition, as recognition is a function of the third skandha. This awareness is not a sensation, which is the second skandha.

For most of us, this is a different way to think about "consciousness."

Why Is This Important?

The Buddha wove his explanation of the skandhas into many of his teachings. The most important point he made is that the skandhas are not "you." They are temporary, conditioned phenomena. They are empty of a soul or permanent essence of self.

In several sermons recorded in the Sutta-pitaka, the Buddha taught that clinging to these aggregates as "me" is an illusion. When we realize these aggregates are just temporary phenomena and not-me, we are on the path to enlightenment.