The complex term, from the latin complexus, to designate which consists of several elements. The name of complex is given to the union of two or more things, the set of plants that are located near each other and under a same technical and financial management and all facilities or buildings assembled to develop a business in common.
That said, a complex consists of several units. For example: 'I have a reservation in a tourist complex before the sea of the Caribbean', 'my city industrial complex continues to evolve and already occupies several acres', 'the father of Lucien has a resort in Cancun.
Also complex, as an adjective, refers to what is difficult, confusing, research or complicated: "it is a complex problem. It amazes me that we can solve it in a few hours","Amanda is a complex person. You never know what to expect with it', "the review was so complex that only three students have been approved."
For psychology, a complex is formed by a set of emotions and repressed and ideas associated with the experiences of the person. These unconscious ideas disrupt the behavior of the subject and have influence on his personality. The Œdipe complex and the Electra complex are some examples.
A complex number is one that expresses the sum between a real number and an imaginary number. Then, in chemistry, a complex is a molecular structure in which an atom or a metal ion is surrounded by molecules with lone pairs.