Each and every are distributive pronouns. A distributive pronoun is a pronoun which refers to people or things one at a time.

Using each

Each is normally used to talk about two or more people or things. It is preferred when we are thinking of people or things separately, one at a time.

Each of the boys won a prize.

When we have to use each in a sentence containing a numeral, each usually goes after it.

The winners received 100 dollars each. (= Each of the winner received 100 dollars.)

I bought the girls two chocolates each. (= Each of the girls got two chocolates.)

These books cost $3.50 each. (= Each book costs $3.50.)

When a pronoun is used to refer back to each, it can be singular in a formal style and plural in an informal style.

Each girl gave her own version of the story. (More formal)

Each student gave his or her own version of the story. (Formal)

Each of them gave their own version of the story. (Informal)

Every

Every is similar to each. It is used to talk about three or more items.

In many cases, each and every can both be used with little difference of meaning. However, every is preferred when we are thinking of people or things together, not one at a time.

The principal praised every boy who won a prize.

Each cannot be used with words like almost or nearly. Instead, we use every.

She rejects almost every suggestion I make. (NOT She rejects almost each suggestion I make.)

She knows nearly every friend I have. (NOT She knows nearly each friend I have.)