Interpreters convey language orally, while translators convey language in writing.
Although language ability is a common skill needed in both roles, the skills needed for the two roles are often quite different. To be a translator you would need to be proficient in reading comprehension, transfer and target language productions skills, along with needing to be able to work efficiently with Computer Aided Translation (CAT) tools, while interpreters need excellent listening skills, a high level of spoken ability, clear pronunciation in both languages, an excellent memory and the ability to think and speak in two languages at the same time.
You can read more about interpreting skills in our blog How to Improve Your Consecutive interpreting Skills.