Free verse may or may not rhyme, and the rhythm varies from line to line.
Example of Free Verse
Song of Myself
by
Walt Whitman
I celebrate myself, and sing myself,
And what I assume you shall assume,
For every atom belonging to me as good belongs to you.
I loaf and invite my soul,
I lean and loaf at my ease observing a spear of summer grass.
Complete poem --
Song of Myself