What is nonnative translator; language translation services
When a person is born, his parents take care of him using the language they communicate with each other irrespective of child age. It does not matter if the child is one day old or not born yet. However, parents still talk about him despite knowing that the child does not listen to them and does not understand even a single letter of their conversation. Nevertheless, parents very well know that their son will start learning his parents' language from the day one that is why they keep talking to him until he becomes an infant then a child and then a boy and then an adult.
The language that the child learnt from his parents is his mother tongue because he heard first work from his mother in her lap.
Sometimes, parents speak one language but sometimes parents speak two or multiple languages with their kids. It happens when the father's, mother's tongues are different. However, a child learns both languages very well. For example, a child born to Indian parents speaking Hindi language will learn Hindi language and Hindi will be his mother tongue or native language.
A child being born to Russian parents speaking Russian language will speak Russian language. If a child is born to parents, speaking two different languages will speak two languages. Suppose, mother speaks Russian and father speaks Hindi, then he will be able to communicate in Hindi and Russian and Russian and Hindi will be his native languages.
In translation, the importance is given to native translators because they understand the language very well and are aware of famous proverbs and jargon. A native translator is supposed to translate a document in his mother tongue very well but translating into a language, which is not his mother tongue, or native language affects language quality.
That is why language translation services provider prefer to native translators in comparison to nonnative translators.