Everyday and every day are commonly confused in English. There's no difference in pronunciation, but using the wrong one when writing is a mistake in the everyday English you use every day.
Everyday is an adjective that means commonplace, ordinary, or normal.
These shoes are great for everyday wear
You shouldn't wear an everyday outfit to the wedding
Don't use the everyday dishes - it's a special occasion
Every day means "each day."
I go to the park every day
I have to work every day this week except Friday
Every day I feel a little better
The Bottom Line
Everyday is a single word and is an adjective, so it's the one that is used in front of a noun to describe something as normal or commonplace. Every day is an adjective (every) plus a noun (day), and it means each day.