what are figurative devices?why are they used in poetry?

makes maximum
use of a sense of language, a feeling for words. The meanings, whether denoted or suggested, all
add to the overall import of a poem. So in order to utilize the possibilities of words, poets
employ figurative devices. Here are some of these devices:

- Language that appeals to the various senses. There are
various types of sense representations: 

1. visual


2. auditory
3. olfactory
4. gustatory


5. tactile
6. organic
7. kinesthetic

- a stated comparison between two unlike
things or ideas using the words as or like. Sometimes
than, similar to, resembles, or seems are used, as
well.
 - an unstated comparison between two unlike things
or ideas. Sometimes the two terms are named, but often one of them, the literal or the
figurative term, are simply implied.
Apostrophe - the
addressing of something non-human or someone absent as though this being or entity is alive and
able to respond
- the attribution of human qualities to
non-human entities or ideas.
Synecdoche - the use of part
for the whole  e.g. "The hand of God"
Metonymy -
the use of something closely related for the thing actually meant. e.g. "The pen is
mightier than the sword."
- An apparent
contradiction that provokes thought into a deeper meaning

- A play upon the meaning of words. e.g. a dying Mercutio tells Romeo, "Tomorrow you will
find me a grave man." grave/serious; grave/place for the dead
Tone -
The author's attitude toward his/her
subject
- A contrast between what is said
or what happens and what is meant or expected.
Symbol -
Something that stands for someone/something
else