You can easily get confused with what’s a verse and what’s a prose. At first sight everything seems quite simple: in one there is a rhyme, but in another there is no. But there is the so-called blank verse or the Japanese haiku or tanka, where there is no rhyme and yet they are poems. So how to distinguish and define verse from prose in this case?
How to define verse? The verse has 2 meanings but they are pretty simple:
As you have already understood, verse in poem is also called stanza. Every poem has its own structure and is divided in some way.
Defining the term stanza above, the requirement of regular repeatability was emphasized as an obligatory feature of verse in poem. However, there are poetic genres in which the repetition of a stanza is limited to a more or less tangible analogy, in some cases, it turns out to be quite distinct in order to preserve its compositional functions behind such a non-strict stanza.
The blank verse is written in compliance with metric norms, the only missing thing is rhyme. There is no compliance of the metric in free verse, has not been and should not be, except of a coincidence in individual lines. The division into lines in the free verse is dictated by means of the creation of a “phrasal rhythm” and the drawing of reader’s attention to certain key points of the poem.
So, the difference between blank verse and free verse is the presence of rhythm – the first one has it while the second one doesn’t.