The word “Da’wah” in Arabic simply means to invite (call) to something. When it is used in conjunction with Islam it is understood to mean “Inviting to the Way of submission and surrender to God.” Dawah is an obligation for all Muslims.
“Invite (all) to the Way of thy Lord with wisdom and beautiful preaching; and argue with them in ways that are best and most gracious: for thy Lord knoweth best, who have strayed from His Path, and who receive guidance.“
(Qur’an 16:125 – YUSUFALI)
“Call unto the way of thy Lord with wisdom and fair exhortation, and reason with them in the better way. Lo! thy Lord is Best Aware of him who strayeth from His way, and He is Best Aware of those who go aright.”
(Qur’an 16:125 – PICKTHAL)
“Call to the way of your Lord with wisdom and goodly exhortation, and have disputations with them in the best manner; surely your Lord best knows those who go astray from His path, and He knows best those who follow the right way.”
(Qur’an 16:125 – SHAKIR)
According to modern Islamic theology, the Qur’an is a revelation very specifically in Arabic, and so it should only be recited in the Arabic language. Translations into other languages are necessarily the work of humans and so, according to Muslims, no longer possess the uniquely sacred character of the Arabic original. Since these translations necessarily subtly change the meaning, they are often called “interpretations.” For instance, Pickthall called his translation The Meaning of the Glorious Koran rather than simply The Koran.