This is the 834th most frequent Dutch word.
iedere
"Every" or "each."
Here, 'iedere' is used to mean 'every' to indicate the repeated, regular occurrence of an action each month.
Ik geef iedere maand een boek cadeau aan mijn vriendin.
I give a book as a gift to my girlfriend every month.
In this sentence, 'iedere' is combined with 'keer' to express 'every time', referring to each instance the described condition occurs.
Iedere keer als het regent, neem ik een paraplu mee.
Every time it rains, I take an umbrella with me.
In this sentence, 'iedere' is used to mean 'every', referring to all students individually within the context of the sentence.