The role of a definite article in the offer consists in the indication of an obvious, unambiguous and concrete subject or phenomenon. Use and understanding of value of an article makes big complexity for people whose language has no similar to a part of speech.
English
In English there is only one form of a definite article - "the". For understanding simplification why "the" in offers is used it is necessary to remember that this article came from the word "that" which means "this". Its role consists in the instruction concrete and all of the known subject, the person or the phenomenon. At the same time definiteness has different origin. It can be a unique thing around the world or in this room, the country. The same concerns also people.
The definite article is put before a word which in the previous offer was selected uncertain. Also "the" surely occurs in names of printing editions, public institutions, in polysyllabic names of the countries. Example: United States of America.
"The" is used with some place names, for example, of the Atlantic Ocean, the Amazon, the Bay of Biscay, the Adriatic Sea, the Hebrides, the English channel. And also designation of group of objects or people, for example, if it is about nationality or subculture.
French
In French the definite article differs on childbirth. Before the words of a feminine gender the article has the la form. For definition of noun gender it is necessary to consult a dictionary. The letter "f" designates the words of a feminine gender. It can be determined also by the termination. The same concerns also nouns of a masculine gender which are followed by a form of a definite article "le". If the word costs in plural, then what sort it would not be, the definite article has the las form. The French definite article has the same semantic value, as English. That is it is written before nouns which designate unique objects or people. For example, months of year, heavenly bodies, etc. Also if it was told about a subject or the person already earlier. The article surely is present if it is told about a subject which belongs to someone concrete.
German
In German the definite article inclines both on childbirth, and on cases. On it, knowing all forms of an article it is possible to understand what sort, a case and number a noun at once. The German definite article is used practically in the same purposes, as English and French. Still it is used for formation of nouns from verbs, adjectives, etc.
Spanish
The definite article in Spanish has several forms depending on a sort and number of a noun. In singular for the words of a feminine gender "la", for a masculine gender - "el" is used. Plural, in turn, is expressed by "las" and "los" for a feminine and masculine gender respectively. Functions of an article coincide with the same functions of definite articles in the English, French and German languages.