Word choice

Both words have similar usages and meaning, but there is a slight difference in their application. 

"Each" always refers to the individual, as in "Each one must decide for himself."

"Every" indicates all, but in a singular, group sense - for example, "Every student in grade 5 got a prize." This means all the students in grade 5 got a prize.  But, to underscore individuality, you would say, "The teacher gave each student in grade 5 a prize." That shows that each one got a prize.

When indicating regular timing/all/how often something is done, you would say: "I wake up at 5am every day" - means I wake up on all days at 5am. Again, if you cannot make a regular generalization, then you would say, "He wakes up at a different time each day."

Also, you would use "each" when referring to quantities of two - such as, "She has a ear ring in each ear."

Hope his clears up some of the confusion.

Shaila