A "free poem" typically refers to a form of poetry that does not adhere to a specific structure or rhyme scheme. It is also known as "free verse" or "open form poetry." Unlike traditional forms of poetry, such as sonnets or haikus, which have strict rules regarding rhyme, meter, and line length, free poems have more flexibility.

In free poetry, the poet has the freedom to use various techniques, such as:

1. Varied line lengths: 

Lines in free poems can be of different lengths, and they don't have to conform to a specific meter.

2. No rhyme scheme: 

Free poems do not require a specific rhyme pattern, so poets can use rhyme if they choose, but it is not obligatory.

3. Unconventional structure:

 Poets may use unconventional structures or no structure at all, allowing for more creative expression.

4. Versatile language:

 Poets in free verse can use language in a less structured manner, often focusing on the natural rhythms of speech and the emotions and ideas they want to convey.

The absence of these traditional constraints in free poetry allows poets to experiment with language, form, and content, making it a versatile and expressive form of poetry. It's important to note that while free poems lack the rigid structure of traditional poetry, they still require careful consideration of word choice, imagery, and other literary devices to create meaningful and impactful verse.

"Free poem" is not a widely recognized term or category in the world of poetry. If you are referring to poets who are known for writing free verse or free-form poetry, I can certainly provide you with some famous poets who have worked in this style. Free verse poetry is characterized by the absence of a regular meter or rhyme scheme, allowing for more freedom and flexibility in the structure of the poem.

 Here are some renowned poets who have written in this style:

1. Walt Whitman:

Whitman is often considered a pioneer of free verse in American poetry, particularly in his collection "Leaves of Grass."

2. E.E. Cummings:

Cummings was known for his unconventional use of typography, grammar, and structure in his poems, creating a distinct form of free verse.

3. Langston Hughes:

 Hughes often used free verse to capture the rhythms of jazz and blues in his poetry, making it a vital part of the Harlem Renaissance.

4. Allen Ginsberg:

Ginsberg's poem "Howl" is a famous example of free verse poetry that was a significant work of the Beat Generation.

5. William Carlos Williams:

Williams employed free verse in his modernist poetry, which often explored the everyday life and language of ordinary people.

6. Sylvia Plath:

Plath's collection "Ariel" contains poems that use free verse to convey her intense emotions and personal experiences.

7. Adrienne Rich:

 Rich's free verse poetry often addressed social and political issues, and she played a pivotal role in feminist literature.

8. Rainer Maria Rilke:

 Rilke, a German-language poet, is known for his free verse works like "The Book of Hours" and "New Poems."