What is the difference between a stanza and line?

A line is a single horizontal row of words in a poem. A stanza is a group of lines that are related to each other and form a unit within the poem. Stanzas are typically separated from each other by a space or an indentation.

Here is an example of a stanza from the poem "The Raven" by Edgar Allan Poe:

```

Once upon a midnight dreary, while I pondered, weak and weary,

Over many a quaint and curious volume of forgotten lore—

While I nodded, nearly napping, suddenly there came a tapping,

As of some one gently rapping, rapping at my chamber door.

```

This stanza consists of four lines, each of which is ten syllables long. The lines are related to each other in that they all describe the speaker's experience of hearing a tapping at his door. The stanza is also indented from the rest of the poem, which indicates that it is a new unit.