Metonymy and Synecdoche : Figure of speech

I can never remember these two words. I often have difficulty remembering few words so I decided to write them down, here and hope I can remember where I have written it down the next time I need to use it.

So what are Metonymy and synecdoche?

They are figure of speech.

what is a figure of speech?

A linguistic technique used to convey a meaning beyond the literal definition of words. They are used in a non-literal, imaginative way.

Example?

Metaphors, Similes, Personification, Hyperbole, Irony, Oxymoron, Onomatopoeia, Alliteration... and many more.

Need further clarification!

Metaphor

Directly compares two unrelated things without using "like" or "as."

"He is the black sheep of the family."

Simile

Compares two different things using "like" or "as."

"She looks like an angel"

Personification

Human characteristics are attributed to non-human entities.

The wind whispered through the trees.

Hyperbole

An exaggerated statement or claim not meant to be taken literally.

"I've told you a million times."

Irony

The intended meaning is different from the literal meaning. It can also mean an unusual or unexpected part of a situation, that seems strange or amusing.

"The fire station burned down."

Oxymoron

Combining Contradictory term.

"Awfully Good"

Onomatopoeia

Imitates the sound it represents.

"Buzz" (The word "buzz" imitates the sound of a bee.)

Alliteration

The repetition of consonant sounds at the beginning of adjacent or closely connected words.

"Peter Piper picked a peck of pickled peppers."

So what kind of 'figure of speech' is Metonymy and Synecdoche ?

Metonymy	Synecdoche
A word or phrase is used to represent something else with which it is closely associated.	A part of something is used to represent the whole, or vice versa.
The substituted word is not part of the thing it represents but is often related to it in some way.	Unlike metonymy, synecdoche involves a direct substitution of one word for another based on a part-whole relationship.
"The pen is mightier than the sword." (Here, "pen" represents writing or communication, while "sword" represents military force or violence.)	"She's studying Shakespeare." (Here, "Shakespeare" represents the entire body of Shakespeare's works or literature in general.)

Since I find all of them quite confusing, I made myself this easy to remember list.