A Rubaiyat is a type of poem that utilizes quatrains in the execution of its expression. A Rubaiyat is (the plural form of rubai) a Persian created concept of poetry, composed using these quatrains. Interestingly, the word "Rubaiyat" is the plural form of the word "Ruba" (which means four). To understand the Rubai, you must first know your way around a quatrain. A quatrain is, as one might expect, a group made up of four parts. Derived from the French word, "quatre" (which was originally derived from the Latin word "Quattuor"), this word has been in use since the sixteenth century. More specifically, in relation to poetry, it is composed of four lines of text. Each rubai can contain as many or as few four-line paragraphs (quatrains) as the writer wishes. These "poetic paragraphs" are called stanzas.
Within each stanza of a poem, you will find a rhyme. With rubai, there is a specified pattern by which these quatrains must rhyme. This is called the meter. The rhymes must occur as follows: AA, bA
An example would be:
I came to teach you to rhyme (A)
and pen verses, so sublime (A)
if you listen close, to me (b)
you'll pick it up in no time (A)
In short, to write a proper rubai, the stanzas of your piece must follow the AA, bA meter. There is no room for error, in this detail. A rubaiyat contains stanzas of four lines of verse. Each stanza will have lines 1,2, and 4 rhyming. Line 3 is free, and does NOT rhyme with the other lines of verse.