Here’s an important basic:
“The rhythmical pattern of stressed and unstressed syllables in verse. The predominant meter in English poetry is accentual-syllabic. See also accentual meter,syllabic meter, and quantitative meter. Falling meter refers to trochees and dactyls (i.e., a stressed syllable followed by one or two unstressed syllables).Iambs and anapests (i.e., one or two unstressed syllables followed by a stressed one) are called rising meter.”
While a foot refers to a single basic unit of measurement within a meter (say one iambic foot of one unstressed and one stressed syllable), think of meter as a way to describe a collection of feet. A series of iambic feet (unstressed, stressed, unstressed, stressed, etc) establishes the verse as having an iambic meter.
Whether the meter is constant throughout, or switches (say, from iamb to trochee, or any of the other various rhythms), the selection should be meaningful and accentuate the work.
I couldn’t imagine this one from Shel Silverstein in prose. Excellent wind up for that zinger at the end.
Where did you get such a dirty face,
My darling dirty-faced child?
I got it from crawling along in the dirt
And biting two buttons off Jeremy’s shirt.
I got it from chewing the roots of a rose
And digging for clams in the yard with my nose.
I got it from peeking into a dark cave
And painting myself like a Navajo brave.
I got it from playing with coal in the bin
And signing my name in cement with my chin.
I got if from rolling around on the rug
And giving the horrible dog a big hug.
I got it from finding a lost silver mine
And eating sweet blackberries right off the vine.
I got it from ice cream and wrestling and tears
And from having more fun than you’ve had in years.