If two or more consecutive lines are short enough, their lyrics will be grouped onto the same line. In that case, they are separated by - to indicate that they are actually different lines. This is important because of the connection between lines and pairs of chords.

Take this example:

[Verse] (Am Am F F x2) - C G F Dm
Psychic spies from China - Try to steal your mind's elation
Little girls from Sweden - Dream of silver screen quotations
And if you want these kind of dreams
It's Californication

It breaks down into:

Chords Line
Am Am Psychic spies from China
F F Try to steal your mind’s elation
Am Am Little girls from Sweden
F F Dream of silver screen quotations
C G And if you want these kind of dreams
F Dm It’s Californication