Alliteration is the repetition of the same sounds at the beginning of words or stressed syllables.

For example, the tongue twister “Suzie sells sea shells by the seashore” uses alliteration.

In modern usage, alliteration is most commonly consonantal.

Assonance is the repetition of an identical or similar vowel sound.

The “ee” sound in the sentence “See the bees” is an example of assonance.

Here’s an example poem that uses the “I” sound repetition:

I have a hive

it’s there I thrive

it’s where I hide

my time I bide

to go outside

collect I might

honey to mine

from pollen inside

While it’s not a great poem it give you a general idea of this type poem.

The heroic couplet is an English form that is commonly used in epic and narrative poetry.

It is a poem constructed entirely through rhyming couplets written in iambic pentameter.

These couplets tend to be closed, rather than enjambed.  The heroic couplet  gained its popularity during the 18th century.