What is cosmic dust and what dioes it made up of?

I have heard that there is cosmic dust in universe and outer space but i couldn't get the proper meaning of what exactly it is. Is cosmic dust some kind of solar wind or matter that is responsible for living in the interstellar space ?
I have heard that there is cosmic dust in universe and outer space but i couldn't get the proper meaning of what exactly it is. Is cosmic dust some kind of solar wind or matter that is responsible for living in the interstellar space?