Based on some understanding of the language, it can be concluded that the definition of language is an orderly system in the form of symbols sound used to express feelings and thoughts that language.
So in the sense of understanding the language, it boasts some of the terms as follows:
Language is a system , That is the language that is subject to certain rules of good phonetic, phonemic and grammatical. In other words, language is not free but bound to certain rules.
The system was voluntary language (arbitrary). The system applies in general, and language is a fundamental rule. For example: there are some languages that start a sentence with a noun such as English, and there is a language that started the sentence with a verb. And one can not reject the rules either first or second. So it is not subject to a specific dialect.
The language is basically sound, and humans have been using spoken language before a spoken language just as children learn to speak before learning to write. Many people in the world who can speak verbally, but can not write it. So that language is essentially oral language (speaking), while writing is a form of a second language.