* Line: A single row of words in a poem. It's the basic building block of a poem, like a sentence in prose.
* Stanza: A group of lines in a poem, separated by a space. It's like a paragraph in prose.
Think of it this way:
* Lines are like individual bricks in a wall.
* Stanzas are like sections of the wall, formed by groups of bricks.
Here's an example:
The Road Not Taken by Robert Frost
Two roads diverged in a yellow wood, (Line 1)
And sorry I could not travel both (Line 2)
And be one traveler, long I stood (Line 3)
And looked down one as far as I could (Line 4)
To where it bent in the undergrowth; (Line 5)
(This is the first stanza, made up of five lines)
Then took the other, as just as fair, (Line 6)
And having perhaps the better claim, (Line 7)
Because it was grassy and wanted wear, (Line 8)
Though as for that the passing there (Line 9)
Had worn them really about the same, (Line 10)
(This is the second stanza, made up of five lines)
And both that morning equally lay (Line 11)
In leaves no step had trodden black. (Line 12)
Oh, I kept the first for another day! (Line 13)
Yet knowing how way leads on to way, (Line 14)
I doubted if I should ever come back. (Line 15)
(This is the third stanza, made up of five lines)
I shall be telling this with a sigh (Line 16)
Somewhere ages and ages hence: (Line 17)
Two roads diverged in a wood, and I— (Line 18)
I took the one less traveled by, (Line 19)
And that has made all the difference. (Line 20)
(This is the fourth stanza, made up of five lines)
Notice how the stanzas help to organize the poem's thoughts and create a rhythm.