What's the main difference between "every year" and "annually?"

Native speaker’s answer
Rebecca
"Annually" is slightly more formal in tone but it has the same meaning as "every year." Other similar expressions include "each year" and "per year." Ex: The company has made over a billion dollars in sales annually since 2010. = The company has made over a billion dollars in sales per year since 2010. Ex: Our family has gone skiing every year for as long as I can remember.