Cognition is what goes on in our heads when we carry out our everyday activities. It involves cognitive processes, like thinking, remembering, learning, daydreaming, decision making, seeing, reading, writing and talking.
Experiential and Reflective cognition.

• The former is a state of mind in which we perceive, act, and react to events around us effectively and effortlessly. It requires reaching a certain level of expertise and engagement. Examples include driving a car, reading a book, having a conversation, and playing a video game. In contrast,

• Reflective cognition involves thinking, comparing, and decision-making. This kind of cognition is what leads to new ideas and creativity. Examples include designing, learning, and writing a book. Norman points out that both modes are essential for everyday life but that each requires different kinds of technological support.

Cognition has also been described in terms of specific kinds of processes. These include:

• Attention
• Perception and recognition
• Learning
• Memory
• reading, speaking, and listening
• problem solving, planning, reasoning, decision making
  

Attention is the process of selecting things to concentrate on, at a point in time, from the range of possibilities available. Attention involves our auditory and/or visual senses.
Perception refers to how information is acquired from the environment, via the different sense organs (e.g., eyes, ears, fingers) and transformed into experiences of objects, events, sounds, and tastes. It is a complex process, involving other cognitive processes such as memory, attention, and language.
Vision: With respect to interaction design, it is important to present information in a way that can be readily perceived in the manner intended. For example, there are many ways to design icons. The key is to make them easily distinguishable from one another and to make it simple to recognize what they are intended to represent
Memory involves recalling various kinds of knowledge that allow us to act appropriately. It is very versatile, enabling us to do many things. For example, it allows us to recognize someone's face, remember someone's name, recall when we last met them and know what we said to them last.
Another well-known memory phenomenon is that people are much better at recognizing things than recalling things. Furthermore, certain kinds of information are easier to recognize than others.
Learning can be considered in terms of (i) how to use a computer-based application or (ii) using a computer-based application to understand a given topic.
many people find listening much easier than reading. Specific differences between the three modes include:
Written language is permanent while listening is transient. It is possible to reread information if not understood the first time round. This is not possible with spoken information that is being broadcast.
Reading can be quicker than speaking or listening
Listening requires less cognitive effort than reading or speaking
Written language tends to be grammatical while spoken language is often ungrammatical.
There are marked differences between people in their ability to use language.
People who are hard of hearing or hard of seeing are also restricted in the way they can process language.
Many applications have been developed either to capitalize on people's reading, writing and listening skills
interactive books and web-based material, speech-recognition systems, speech-output systems, natural-language systems, cognitive aids that help people who find it difficult to read, write, and speak. various input and output devices that allow people with various disabilities to have access to the web and use word processors and other software packages
Problem-solving, planning, reasoning and decision-making are all cognitive processes involving reflective cognition. They include thinking about what to do, what the options are, and what the consequences might be of carrying out a given action. They often involve conscious processes. discussion with others (or oneself), and the use of various kinds of artifacts, (e.g., maps, books, and pen and paper).