In our everyday life, how we act or how we understand our surroundings are cognition which is a set of in-born mental abilities of human. Through different cognitive processes (problem-solving, reasoning, acquiring knowledge, etc), people are able to use the existing knowledge to generate new knowledge.
Figure 1 : Different cognitive processes that can be done by a human brain (http://i.huffpost.com/gen/2211150/images/)
In performing different cognitive processes, our brains are having many different cognitive abilities and each having their own uniqueness with different skills involved. For example:
(1) Attention [People can concentrate on a particular thought, object or action as well as able to manage demands in a competitive environment]
(2) Memory [People can memorise things in a short-term or long-term period which stores in their brain for other uses]
(3) Language [People having skills that help to translate sounds that are heard into verbal outputs which can also help express their opinions]
By applying different skills to perform the abilities, people should well use each of them to have a better performance in different activities. These abilities can be boosted up by joining different physical activities that can improve ones memory as certain hormones are produced during the physical activities. Also, reducing chronic stress can decrease damage towards the brain and will not easily give rise to mental problems.
So, it is important to improve our daily habits and do more exercises to optimise cognitive function.
Ref: 1) What are Cognitive Abilities and Skills, and How to Boost Them? By: Dr. Pascale Michelon [http://sharpbrains.com/blog/2006/12/18/what-are-cognitive-abilities/]