The following text is taken from
The Poets Graves website.Iambic meterAn end stressed two syllable foot
e.g. from In Memoriam by Lord Tennyson
I DREAMED | there WOULD| be SPRING | no MORE
This example is an iambic tetrameter - i.e. it has four iambic feet and therefore the total number of syllables in the line is eight. Iambic is an example of rising meter.
Trochaic meterA front stressed two syllable foot.
e.g. The Song of Hiawatha by Henry Wadsworth Longfellow
BY the | SHORES of | GIT chee | GUMee,
This example is trochaic tetrameter - i.e. four two syllable feet. Therefore the total line has eight syllables. Trochaic meter is less commonly used than iambic meter. Trochaic is an example of falling meter.
Anapestic meterAn end stressed three syllable foot
e.g. The Destruction of the Sennacherib by Byron:
And the SHEEN | of their SPEARS | was like STARS | on the SEA,
This line is an anapestic tetrameter i.e. it has four feet containing three syllables each. Therefore the total number of syllables in the line is twelve.
Dactylic MeterA front stressed three syllable foot
e.g. The Lost Leader by Robert Browning
WE that had | LOVED him so, | FOLlowed him | HONoured him,
This line is an example of dactyllic tetrameter i.e. it has four feet containing three syllables each. Therefore the total number of syllables in the line is twelve.
Each of the above meters can be used in lines with varying numbers of feet. The number of feet in a line is usually classified as follows: monometer (one foot), dimeter (two feet), trimeter (three feet), tetrameter (four feet), pentameter (five feet), hexameter (six feet), heptameter (seven feet) and octameter (eight feet).
More information on meter
Basics of Poetic Form, Meegan Kennedy, Florida State U
Wikipedia meter entry