The difference between poetry and poem is not a big one but there is a small difference. A poem is one type of penning down a literary piece. The process of writing a poem is called Poem and is also a form of artwork. Both of them have a slight difference and nothing much. A poem is an arrangement of words that have meaningful and musical elements too.
The writer of a poem is known as the ‘author’ who shows and explains his dreams, happiness, sorrow, excitement, nervousness, and many such feelings through words in the poetry. It is not important for a poem to have rhyming words; it can have non-rhyming words, it can be simple, and complex respectively.
Poetry, on the other hand is a classical word flow that tells what is going on in the mind of the author and makes the readers feel the same. If the poet has written down his/her feelings, then the same will be felt by the readers.
Remember that a poem is a composed form of work, whereas a poetry is the form of an art. Poetry is made up of poems. The one who writes poems on an occassional basis cannot be called a poet but will be called a versifier.