If we seek to understand the term 'retention' in its most basic sense, we must say that it is the act of retaining, containing an element, a product, an abstract entity in a certain space or in the power of a certain person. This term is applied to various situations, always meaning the permanence of an element X without the possibility of being extracted or transferred to another place. Retention, whatever its meaning or application, can be both voluntary and involuntary, spontaneous or planned, internal or external, and the results generated by such retention may also vary from case to case.
One of the most common meanings of the term 'retention' is that which has to do with the retention of ideas, knowledge and information in our memory. This retention is in most cases produced by study, practice and permanent contact with the retained concepts. So much so that a student retains what he studies in his head through different learning techniques.
On the other hand, we also talk about withholding in the economic sphere and this is when it is applied to the conservation of part of a profit or salary by an external agent to the one who generated it. This practice has been common throughout the history of Humanity, especially when we find a strong presence of the State on economic aspects. It can also occur in the private sphere between the employer and the employee without the need for the State to intervene.
Finally, the concept of retention is also widely used when referring to the biological condition of fluid retention. This physiological situation is related to the non-elimination of certain fluids present in the blood and body fluids that cause the body to present some symptoms of swelling and thus gain weight. This weight can be eliminated through urination or sweating and that is when the concept of fluid retention is directly related to different types of diets and eating plans.
