In poetry, these two words often mean the same thing. We use both words to talk about the way a poem is put together; eg, does it rhyme or not? Is it divided into verses (stanzas?) How does it develop, eg is it regular in shape, rhythym, line length, verse length, or does it change to fit the mood or ideas the poet wants to convey?
The word "form" is also used in a more precise sense, to mean a particular type of poetry. In this sense there are a number of well known poetic forms; these fixed forms are sometimes called "mechanical" to make it clear that they are fixed; the poem must fit the form, not the other way round. The sonnet is an example of a mechanical form; a sonnet must have 14 lines and follow a specific pattern of rhyming and line length. (You can find more information on this form on Blurtit, if you type "Sonnet" in the Search window.)
The word "form" is also used in a more precise sense, to mean a particular type of poetry. In this sense there are a number of well known poetic forms; these fixed forms are sometimes called "mechanical" to make it clear that they are fixed; the poem must fit the form, not the other way round. The sonnet is an example of a mechanical form; a sonnet must have 14 lines and follow a specific pattern of rhyming and line length. (You can find more information on this form on Blurtit, if you type "Sonnet" in the Search window.)
