The first step we are going to take before entering fully into the analysis of the Cartesian plane term is to proceed to establish the etymological origin of the two words that shape it. Thus, the flat word we can determine that it emanates from Latin and more exactly from the term *planus *which can be defined as "flat".

The notion of **flat** It has different uses and meanings. It can be a **surface that lacks reliefs, elevations or undulations** ; of a **element that has only two dimensions and that houses infinite points and lines** ; or of a **scheme** developed on a scale that represents a land, a building, a device, etc.

**Cartesian** , meanwhile, is a **adjective** that derives from *Cartesius*, the Latin name of the French philosopher **Rene Descartes** (which lived between the end of the 16th century and the first half of the 17th century). The term, therefore, refers to what is linked to **Cartesianism** (the postulates or principles proposed by this thinker).

It is known as **Cartesian plane** to the **ideal element that has Cartesian coordinates** . These are straight parallel to the axes that are taken as reference. They are drawn on the mentioned plane and make it possible to establish the position of a **point** . The denomination of the Cartesian plane, of course, is a tribute to **Discards** , who sustained his philosophical development at a starting point that was evident and allowed to build knowledge.

The Cartesian plane exhibits **a pair of axes that are perpendicular to each other and are interrupted at the same point of origin** . The origin of coordinates, in this sense, is the reference point of a **system** : at that point, the value of all coordinates has nullity (**0, 0** ). Cartesian coordinates **x** and **and** On the other hand, they are called **abscissa** and **tidy** , respectively, in the plane.

In the same way we cannot ignore another series of elements that are fundamental in any Cartesian plane. In this way, we find the origin of coordinates, which is represented by the O and that can be defined as the point at which the aforementioned axes are cut.

Likewise, it is also necessary to refer to what is called abscissa of the point P and the ordinate of the point P. And all this without forgetting that in any Cartesian plane various functions can be carried out such as the linear ones, those of linear direct proportionality and indirect proportionality.

The former are identified by the fact that in them all points are aligned. Meanwhile, the latter are carried out by the presence of what is known as a proportionality constant, which is identified by the letter k, and by the fact that in them if in the pairs of values the ordinate is divided by the abscissa always Get the same number.

An operation is different from the one that occurs in the functions of indirect proportionality because in them what is produced is the multiplication of the ordinate by the abscissa in the pairs of values. The result will always be the same number.

In a flat coordinate system, which is formed by two perpendicular lines that are cut at the origin, each point can be called through **two numbers** .